Though I don't understand Japanese, I think the joke is that he's depressed because, despite there being some free urinals, he went into the stall to pee out of habit.

Sometimes when you have to go, you HAVE to go, it doesnt matter much if its in a male bathroom urinal or behind a tree

The character is disguised as a girl in the "idolmaster" anime series. He is so used to avoiding urinals (because he's supposed to be pretending to be a girl), that he ignores them when he is in "boy mode."