It's a different shoe. Your F last pic is of an austerity brogue oxford. The U last pic is of Vass's "River", which is basically a balmoral with the vamp and facing in one piece. The patterns are fundamentally different, I guess they made the wing tip different too. But even if they didn't, the more pronounced toe of the U and the smooth vamp and facing, is going to make it look proportionately shorter.