A joebag is a milder form of a douche bag. Joebag personalities usually include mild rudeness, arrogance, snobbery, dumbness, and immature tendencies, but still have the capacity to be nice and show some compassion. Also, an "I'm-too-cool-for-school" wardrobe can sometimes be classified with joebags. Usually, they are completely oblivious to their actions and can be laughed at by outside parties.
person 1: did you see his pants? they were below his knees! and he told me i was fat...
person 2: my god, he's such a joebag!