I strongly disagree about the photo having to be of the seller.
A picture or photo of anything that is interesting to the seller, (as long as it's legal, & doesn't break copyright rules) is all that is needed.
A little personal info is fine, plus information about the sort of items you sell, what your terms are, how you pack items, deal with returns is what the About Me page is for, it's to give those you deal with, a feeling for the sort of person (or business) you are, to help them decide whether they want to deal with you or not.
It's not a dating site, so how you look, or dress, has no bearing on that at all.