Yeah, I think other than not wanting the opponent to see his sparring sessions, Mayweathers camp (and 24/7 for that matter) probably do it for the "WOW" factor.

It's all very dramatised and attempts to put Floyd up on a god-like pedestal.

*Garage Doors Go Down*
*A massacre takes place*
*Camera Returns*
*Blood is everywhere and Mayweathers opponent is half dead*

It just tries to enhance Floyd's myth as being the best boxer on the planet and psyche out the opponent.