This GIF is overflowing with narrative. Maybe this guy just found out he's actually wearing a Cardinals jersey, something he would be understandably embarrassed and upset about.
What actually happened is that he found out Fitzgerald, whose jersey he's wearing, got a flag for offensive pass interference. Aww, man. He was so pumped to wear his Fitz jersey to the game.
As for the pair of Niners fans behind him, we'll turn that over to you, dear readers. Spin your own story for father-and-son 49ers fans.