I actually went and asked a female physicist about it. Her response if she'd been at this lab when younger (older academics develop a very, very thick skin it seems) then yes she would have found it (a lab head with a shirt emblazoned with nearly naked women on it) very off putting probably to the point of not going there.
Anecdotes mean nothing, and here's why: My wife's favorite t-shirt has an almost-nude Bettie Page in full dominatrix gear, and she happily wore it to work when we first met (albeit she's not a physicist or in academia, but she does work in the tech realm.) The difference? She's completely secure in her self-image, and in her femininity - enough that she doesn't give a damn about what some guy wears.
...at making a group feel completely excluded.
What group - militant feministas who are so insecure in their self-image that they have to lash out at the planet? In all honesty, fuck them. I get the whole professional attire business, but I refuse to attenuate my life or attire out of fear that I might somehow offend the perpetually-offended.
If the group you refer to is simply 'women in general'? Sorry, but that group is way too damned diverse to be put into a container, and the dude's shirt wasn't pornographic, so what the hell?