Nf6 would have been the Two Knights defence and playing that attacks the e4 pawn. In that sense Nf6 provides some tempo to black as white has to consider how to defend the e4 pawn. Nf6 is probably more logical in that sense so would be seen by players who haven’t studied the Italian game.
Giuoco Piano means the quiet game because down this line there is less exchange and competition for the centre and instead each side continues steadily with development. However it does contain some more aggressive lines so as long as you avoid the Giuoco Pianissimo (Very Quiet Game) you still have opportunities to have a good game. You will find some pretty scathing commentary on the Giuoco Pianissimo as it leads to pretty much gridlock but beginners will often find themselves in that position. The Giuoco Pianissimo also makes it difficult to beat players who might not be as strong as you because everything is so defensive.
You can see that the obvious next move for White is c3 as this prepares d4 or c4 to attack the Bishop on c5. Black can prevent this with Nf6 which is really the only next option as this attacks the e4 pawn and forces White to consider how to defend it instead of playing b4 or d4 which White would want to play. But we’ll cover that in the next post!
Here’s a nice little video showing a game that uses this position: