UPDATE:  On Friday, the jury cleared venture capital firm Kleiner Perkins Caufield & Byers of discriminating and retaliating against Ellen Pao.

Ellen Pao has one problem that many working women can empathize with: She's not perfect.

Of course, nobody is, male or female--but in the workplace, this seems to be much more of a problem for women, who see their personalities regularly judged and found lacking, even in largely positive performance reviews. If you're a professional woman, the critiques may sound familiar: Her work is great, but her "tone" is a bit harsh. She's an expert in a particular technology, but her colleagues find her cold.

Successfully responding to these maddening critiques takes time and energy that could be better spent on, well, anything else, and in many cases, not a little self-abnegation. Pao, like many self-respecting women, seems not to have been up for that.

Now, these sorts of ambiguous comments are at the heart of Ellen Pao's closely-watched lawsuit against venture firm Kleiner Perkins Caufield & Byers. The case is not at all clear-cut: Pao did receive lots of positive reviews, in addition to the negative ones, and one of her early investment picks went public. She also had an affair with a married partner. Among venture firms, it can be argued that Kleiner's done a better job promoting women than many. But Kleiner also hosted all-male social events. On a business trip, one partner (no longer with the firm) tried to force his way into a female colleague's hotel room. The verdict, no matter how it comes down, is going to be seen as a referendum on Silicon Valley culture.

In one sense, Ellen was like most of her peers: The vast majority of newbies in venture firms, no matter their accomplishments or gender, do not become investing partners. To determine if she would get promoted, Pao seems to have been held to standards that go well beyond her investment returns, her knowledge of particular companies or technologies, or her success at sourcing deals.

Instead, like many women, she was asked to walk a tightrope--one that had as much to do with her personality as her investing ability.

Some women, most recently and notably Sheryl Sandberg, are so good at this that they make it look easy.  That's all the more frustrating for everyone else, who becomes understandably flummoxed when asked to be--at the same time-- both authoritative and feminine; take-charge and nurturing. In another era, this added cognitive load was probably best expressed by cartoonist Robert Thaves, who wrote that, "Ginger Rogers did everything that [Fred Astaire] did, backwards... and in high heels."

A study by linguist and Textio CEO Kieran Snyder, which I wrote about last summer, illustrates what the non-Sheryl Sandberg experience looks like for many women, not just Ellen Pao. Looking at 248 performance reviews, almost all of them positive, Snyder found that men tend to be criticized because they fail to develop or exhibit certain skills. Women get dinged for perceived personality flaws.

Here's a quote from a review that was critical of a man:

There are a few cases where it would have been extremely helpful if you had gone deeper into the details to help move an area forward.

Here's one that was critical of a woman:

You can come across as abrasive sometimes. I know you don't mean to, but you need to pay attention to your tone.

It's not a close call. In the 83 critical reviews received by men, just two included comments on personality. In the 94 critical reviews received by women, 71 included negative comments about personality.

The negative comments lobbed at women were the same ones that capable, professional women have heard over and over and over: The dreaded "tone" complaint, above. You're too aggressive. You need to let others share the limelight.

Is it even remotely possible that 2.4 percent of the men have personality flaws that affect their work, but 76 percent of the women do?

The criticisms lobbed at Pao by some of her colleagues at Kleiner were remarkably like the ones unearthed in Snyder's study.

Ted Schlein, a partner at Kleiner, wrote of Pao: "She seems passive, reticent, waiting for orders in her relationships with CEOs." When one such CEO, Mike McCue of Flipboard, positively gushed over Pao's involvement in his company, another Kleiner partner, Matt Murphy, dismissed those statements, saying McCue was an "enthusiast."

The description of Pao as a wallflower is also a bit hard to square with the fact that Murphy also referred to her as "pushy" and "entitled." Murphy said that the fact that Pao had a "professional" relationship with the partners in the firm wasn't enough: She didn't have the right "chemistry" with them. "In all these things it was professional, but there's a certain chemistry with people," he said, according to the excellent blow-by-blow coverage on Re/Code. "Are they really collaborative? Do they enjoy working together? Do they want to work together?"

In Pao's 2011 peer reviews, the phrase "very collaborative" appeared at least three times, again according to Re/Code. Apparently, that wasn't collaborative enough, as Pao was not promoted, even as her colleague, Chi-Hua Chien, with a less impressive investing record, was.

In Pao's reviews, co-workers, including Chien, described her as territorial, difficult, harsh and demanding credit -- traits that were cited as factors in her termination. In Chien's own reviews, he was described in similar terms, but was promoted.

None of this takes into account the other bad behavior Pao faced, or Pao's own poor decisions while at the firm. It does show that for Pao, as for many of the women in Snyder's study, simply being excellent at the job at hand isn't going to get you very far.