Google for Entrepreneurs held its first "women's edition" demo day Wednesday, showcasing 11 female-led startups in front of an audience of investors, journalists, and entrepreneurs. The event was meant to help close the gender gap in the technology world, but attendees left with an inadvertent symbol of why that gap exists in the first place.

On exiting, each attendee received a swag package containing a notebook, a pen, a package of mints, and a mirror. The kit, components of which were embossed with the words "Showcase Yourself," was meant to contain all the items one needs to prepare for an on-stage pitch.

But to some, the kit--in particular, the makeup-compact-style mirror--was a reminder of the double standard that too often constrains women in Silicon Valley to prescribed roles, when it's not excluding them entirely. For one of the most admired tech companies on earth to give out makeup mirrors at a women's event--what kind of message does that send?

"It seems kind of weird to me," says Rachel Sklar, founder of Change the Ratio, an organization devoted to increasing visibility of women in tech and new media. Sklar, who also founded media platform and exclusive women's professional network, wasn't present at the demo day, but Inc. showed her a photo of the box with its contents.

She questions whether Google would have included a mirror in a gift box or bag distributed at a non-gendered event or an event dominated by men. Perhaps the mirror's inclusion in a package made for an event where the brand is women is the manifestation of unconscious bias, she suggests: "I think it's reasonable to assume gender is the reason."

Indeed, while diversity and gender parity have been hot conversation topics in Silicon Valley for the past couple years, it seems every week offers fresh evidence of just how hard it is to retire hackneyed stereotypes. Just recently, IBM faced criticism for an ad campaign asking women engineers to hack hairdryers. Last week, venture capitalist Michael Moritz of Sequoia Capital said his firm wouldn't lower its standards to hire more women.

Defending the choice of swag items, Google points out that the kit was meant for attendees. Half of those in attendance were men, according to the company. Remaining boxes were shared after the event with the (mostly female) entrepreneurs presenting. The idea was to hand out materials that would help anyone of any gender prepare for a presentation, a Google representative explains. This wasn't the first time the company has given out mirrors, either--they've done so at general events and trainings. 

That explanation was good enough for some of the women entrepreneurs who attended the event. 

"I could see the mirrors being a bit obtuse if they weren't part of a presentation prep kit," says one founder, who requested anonymity because she's hoping to build a relationship with Google. "Apparently, the idea of the kit is for you to have everything you need when preparing for a presentation or meeting. Given that, I could see many people being curious about how they look." (Never mind that many of Silicon Valley's iconic male founders are known for their total indifference to style and grooming.)

"I'd also rather pick my battles," the founder continues, explaining that what really struck her was the gender imbalance at Google Ventures' CEO summit earlier in the week. "I don't know how many women there were founders of GV-funded companies, but they were scarce" among the more than 300 companies represented, she says.

Other female entrepreneurs not present at demo day, who either saw images of the box's contents or who heard descriptions of the contents, gave mixed responses to the mirror.

Fay Johnson, founder of Oakland, California-based lifestyle brand startup deliberateLIFE, wasn't so much bothered by the mirror as she was by the whole idea of a women's demo day.

"I think it's walking a line--however, I would say we have expectations that men are 'presentable' on stage, too," she says, adding that mirrors also carry the deeper symbolic meaning of self-reflection. "I'm not sure I'd pick on the mirror--but I do have an opinion on the women-only demo days. I think they are a token that doesn't address the real issue," namely, the dearth of women in tech. "I want to play at the same table as the boys, not a separate, segregated one."

"When it comes to women, Silicon Valley has this paternalistic, dumb-it-down way of thinking, which is: Give them something that makes them feel pretty, because that's all they really want," says a woman CEO whose startup recently raised money in the Bay Area. "That's a way of thinking that might work with their girlfriends but not an entrepreneur/businessperson."

Sklar cautions that she wouldn't want to see discussion of a mirror overshadow the mission of the demo day to promote entrepreneurship among women. The mirror is just a small data point, she says-- but it's one of many small data points that make up an environment in tech where women are marginalized. "That's why it matters to call them out" on distributing the mirror, she says.

The tech industry has made some strides in recent years with regard to increasing gender diversity. The number of women-led VC firms is increasing, and they're apparently more inclined than other firms to fund women-led companies. Companies reporting gender ratios among staff has become commonplace, and many companies also report racial diversity.

Yet women still remain under-pursued and under-funded. An oft-cited stat: companies with female CEOs received only 3 percent of VC funding between 2011 and 2013. Women own 36 percent of businesses in the country, but lead only 10 percent of the 500 fastest growing companies. The Atlantic reported in 2013 that while women made up 57 percent of the U.S. work force, they held only 25 percent of computing jobs.

In Silicon Valley, those numbers look even worse. Earlier this year it was reported that women made up 30 percent of positions overall at Google, and 17 percent of the company's tech positions. At Facebook, 15 percent of tech roles went to women; at Twitter, 10 percent. Even at the women's edition demo day Wednesday, not all of the female-led companies had female CEOs: Some qualified as female-led because they have women in other executive roles or have female founders, but not female chief executives. In a couple of instances, a woman pitched the company, only to have her male CEO step up and field most or all of the judges' questions after her presentation.

In one way, a mirror may have been--or at least felt like--a clumsy way of anticipating the needs of female founders. On the other hand, it's the perfect symbol for an industry that still needs to do a lot of self-examination when it comes to diversity.

This article has been updated to expand upon comments from Google.