I think a good word for this would be tactless. While some people use the word "vegan" as shorthand for "not eating anything that comes from an animal," the central value of veganism is that animals aren't here for our use, be it clothing, food, or entertainment. Not all vegan restaurants are marketed towards folks who are lifestyle vegans, though.
I think a good analogy here might be places that don't serve alcohol. While they would all probably appeal to people who don't drink, they aren't all marketed specifically towards non-drinkers (or drinkers who are interested in trying a mocktail). If you're going to a hip new place for the heck of it, it probably isn't going to be a huge deal. However, if you go to one that is affiliated with a sobriety program or a faith that eschews drinking, it would be in rather poor taste to wear a tee shirt celebrating intoxication in one way or another.