The individual in question looks like a man to me.
Some butch lesbians look exactly like men and can easily be mistaken for me, especially older women.
I am not a lesbian but did identify as a lesbian in my distant past. I have had intimate LTRs with men and women and am more interested in what goes on in a person's heart and mind than what body parts they possess.
My definition of a lesbian is somewhat different to others here in that if a woman predominantly has relationships with women but is occasionally attracted to / has intimate relations with people who are not women but still says that she is a lesbian I will accept her self-definition.
However, whatever differences I might have with posters here regarding having the state of being a lesbian revoked by the sisterhood should a woman have sex with a man (does it get revoked after one sexual encounter? 2? how many? who decides? etc.) it seems to me to be insulting and ridiculous to suggest that a man / trans woman or even a woman who identifies as gender-fluid should represent lesbians on lesbian visibility day.
Surely, now matter how much a person or group respects diversity, the choice of a person to represent a particular category of people, especially when oppressed and in the process of being erased via the policing of language and collective adherence to logical / nonsensical rules, should be a person who encapsulates the most visible qualities of the category concerned?
So, regardless of whatever disagreements I might have with posters here on a range of issues, on lesbian visibility day the poster woman who represents the category should at very least be a woman who identifies as a woman and whose primary intimate relationships are with other women.