What is a gay beer?

Brodies seem to know as they have produced Brokeback Bitter and Dorothy's Friend (both probably rebadged for a recent gay beer festival in Soho) along with Pink Pride and Ginger Beer - Not sure this last one is directed at the gay scene, but you never know.

Is there a difference between gay and straight beers? Is one more fruity than the other? (sorry, couldn't resist )