In the story "If I Were a Man" by Charlotte Perkins Gilman, how does her description of what constitutes a man's identity differ from that of a woman?

The time setting of Charlotte Perkins Gillman's story determines some of the changes in attitudes that Mollie, the protagonist, feels because in this setting most wives do not work. Consequently, she has had no experience of commuting to work or having her own money or being around men in a setting outside of social gatherings.

When Mollie enters the body of her husband, Gerald, suddenly the world seems to become the right size. Distance is covered with longer legs and feet that can control the ground on which they step. In fact, when she walks, there is a sense of comfort—as there also is when she puts her back against the seat on the commuter train. The discovery of so many pockets in the pants she wears delights her with the convenience of having everything at hand. With great joy

...she felt what she had never felt before in all her life—the possession of money...her own earned money—hers to give or to withhold, not to beg for, tease for, wheedle for—hers.

More and more she feels empowered. Friends are on the train, and suddenly she feels that she has truly entered the world of men because now she experiences how they think on such topics as business and politics and sports. She is even aware of what they have thought before in their lives. As the men talk among themselves, 

...there poured in on the submerged consciousness beneath a new, a startling knowledge—what men really think of women.

It seems that men have two departments of thought. One is that of affection and love—tender ideas, loving ideas. In another department are those stories from parties, "base traditions, coarse epithets, gross experiences," private ideas. These thoughts become dizzying and troubling to her. They are the most foreign of perspectives that she has experienced.

As she looks out the window of the train, a new world that seems larger to her opens. Then, Mr. Miles, a neighbor on the other side of her street, begins to complain of having to give up his seat to a woman. Another man complains that women cannot make up their minds anyway.

"The real danger," began the Rev. Alfred Smythe, the new Episcopal clergyman, a thin, nervous, tall man with a face several centuries behind the times, "is that they will overstep the limits of their God-appointed sphere."

Something inside her bristles. Gerald sits up straight and speaks up for womanhood.

"Seems to me we all talk like Noah," he suggested dryly, "or the ancient Hindu scriptures. Women have their limitations, but so do we, God knows. Haven't we known girls in school and college just as smart as we were?"

Gerald Mathewson defends women further, saying if women have brought evil into the world as Eves, the men have certainly helped to keep this evil going.

Finally, the train pulls into the city and Gerald goes to his job. But all day Gerald becomes slightly conscious of new and strange feelings, different views, and the "submerged Mollie learned and learned."

As a man, Mollie has certainly experienced more independence and more responsibilities, such as working and managing money, dealing with the public, engaging with people all day, and providing for the family in many ways.