Its all about looking like a better team.
The more profesional you look towards any sport, the other team will think, man, they look pro, they must be good.
I played a rugby team yesterday that was all about shouting and wearing tight tops, it was intimidating at the start as off the kickoff you wonder if they are actually any good, and you start douting your own performance compared to their potnetial.
You cant start shouting across the field, but you can enourage your team to look as pro as possible.