VS is trying out a strategy of equalizing star power in the wake of Gisele's abandoning them. Alessandra has won plenty of solo covers (UK GQ x 2, Wurth calendar) so I guess she sat this one out.
I am kind of disappointed that this was shot in black and white. It's almost too tasteful for its purpose, if such a thing could exist. I just imagine a colored spread would be much more enticing.