It's comical because Muntari believes that offering his shirt to the lad will be a momentous occasion for him, but instead he just tries to give it back to him. Whether or not the kid was trying to be rude is not important, it still looks funny.
Kinda reminds me of the Pepsi ad during the nineties where the kid asks for Beckham's jersey only to use it to wipe the top of his Pepsi can, then revealing that he's wearing a Juve t-shirt