[treya]

Messi is doing several things in the referenced video. First, he's staying wide (almost to the touchline) which is drawing the 2 defenders towards him. This increases the open space for attack, but more importantly it betters the overall ratio of attackers to defenders in the active part of the field. He's also intentionally walking. Running, and more so sprinting, causes opposing players to be more aware of you. Walking suggests you aren't actively participating. When the defenders turn their attention to the play, he slowly moves in behind them - this puts him in a more dangerous position (this isn't a great clip to demonstrate this because he ends up having to back up to receive the cross.) Notice also he's positioning himself so he's not substantially closer to one defender than the other - you don't really see the effect of it here - but that will tend to cause both players to cover him. If he can pull two defenders instead of one to cover him, he really doesn't need to do anything else to increase the odds for his team. But space-making isn't the real genius of Messi. His ability and willingness to take on several (or more) players at once, aside from the obvious advantage when he scores in such situations, will draw opposing players to him, opening up the rest of his team for through-passes into dangerous positions where defenders have been pulled out of place.