This week Marissa Mayer marked her first-year anniversary as CEO of Yahoo. I intentionally didn't use the word "celebrated" in that sentence because I don't think anyone feels there's cause for festivities but anniversaries always prompt a little reflection.

So what is there to learn from Mayer's first year?

1. The company was a corpse to begin with.
While the stock price has improved and there are faint signs of life within the business, expecting resuscitation was and is irrational and impossible. That Mayer has kept the corpse warm is remarkable, even if investors and analysts aren't thrilled.

2. Yahoo looks and feels old-fashioned.
Portals, hubs, communities are all old buzz words and nothing Yahoo has done has reinvented or revivified them. The web continues to be a promiscuous place.

3. For as long as I've had a web browser, people have been saying that technology will yield to media.
But it still hasn't happened yet. Technology still counts and I've seen nothing new under the hood of Yahoo for years now. You can change the culture, make people come into the office or stay at home, hire people and fire people, but what counts is whether Yahoo offers anything that consumers can't find better somewhere else.

4. Women leaders have two jobs where men have one.
Women in top jobs always endure more scrutiny than their male counter-parts. A hair out of place, increased or decreased weight, dress styles, and maternal habits are all examined in minute and usually irrelevant detail. This makes their job harder. In addition, many people expect female leaders to be both spectacular and androgynous: commanding, omniscient, and technically brilliant--but also empathetic, nurturing, attractive, and kind. Heightened scrutiny makes real experiment and risk-taking difficult.

In short, Mayer took on an impossible job and will get an undeserved roasting for failing to perform miracles in a single year. But that's the gig she took. Psychologist Alex Haslam calls this the 'glass cliff' phenomenon, in which top jobs for women are so rare that they'll take even the duff and risky ones. The best you can say at the end of year one is that Mayer has done both of her jobs adequately but it's of course still unclear whether the dead will rise again.