It's a long term idea - nothing immediate.
A very common idea is for White to play Nb1-d2-f1-g3(or-e3)-f5, and in many cases, this could be sacrificial (i.e. a Black pawn is on g6).
If Black ever captures, White may take with the e-pawn if it means opening up the diagonal and the c2-Bishop comes to life. Last thing you want to do is trade that thing away for a Knight after you've moved it as many times as you have already.
I never play this opening, but I suppose white wants to play Nf1, which would currently lose the e-pawn to exd4 cxd4 Nxe4?
Nf1 is certainly one of the motives, but i wouldn't say it's the only one since there would be some other ways around to defend e4 for a while, i might be wrong since i haven't analysed this any deep. I think it's safe to say that white is also expecting exd4 that removes the blockage from e4 pawn and allows advancing and controlling the diagonal that can potentially attack on h7.
This opening is Ruy Lopez Closed. White plays Bc2 at the Grandmaster level and I still don't see what the point of it is.