That's like saying "I work as a nurse in a hospital in the 1950s". Sure, you may see some sexism second hand, but if you're a female doctor in the same position, it's a totally different experience.
The primary thing I didn't like about the author's article was that her criticism of the original article (which were totally valid, by the way) kind of concluded with the impression (given by her anecdotal experience) that "sexism isn't as bad as it's made out to be, look, I haven't seen any."
The truth is it is there, and it can be pretty bad in some cases, although these scare articles by the author she was criticizing isn't really giving any meaningful advice on how to do deal with it.
Interesting she works in a big shop... coincides with my experiences that larger orgs tend to be more comfortable/friendly to women.