If you have a close look, you'll realise that they have their heads between the two players in front, not between the thighs of one of them. It's funny how many AFL fans think that way. Could be something Freudian going on there? :p
I was having this same conversation with an ex-pat Vic on Saturday night. He won the argument for me when he described how, unlike rugby players who stay rooted to the ground, AFL players 'float like butterflies'. I nearly spilled my beer. Butterflies!! :D