Oh dear! I seem to have misread. LOL.
I play the closed and Bb5 doesn't look sensible at all.
Bb5 is basically an Accelerated/Delayed Grand Prix. Whereas in the Grand Prix proper, White usually plays 3 f4 g6 4 Nf3 Bg7 and now 5 Bb5, in this line White accelerates the Bxc6 threat while delaying the f4 plan. It's a Rossolimo with ...Nd4 available for Black, c3 and d4 unavailable for White, but f4-f5 available.
It's acutally been played alot in 2013-2014 and White has 48% Win. It looks very sensible to me. 3.f4 and 3.g3 seem to have a higher win rate for Black but maybe I shouldn't pay too much attention to that.