About T-Shirt Design
The joke on WARNING The Girls are Drinking Tonight T-Shirt is easy to understand, and that is a big part of why it works. Fans of everyday humor will probably get the joke first, but it is simple enough for almost anyone to understand.
It makes sense for birthdays or holidays, especially if the person already likes this kind of humor. It has the relaxed feel people usually want from novelty shirts without getting too complicated. The design is easy to get, easy to gift, and easy to wear without overthinking it.