Marleny, as a non-pro I have a difficult time criticising other people's work when I like the subject and overall composition. It is what it is...a little boy sitting with a snack with a big smile on his face. I think it is a little soft in focus - perhaps that was your intent? My only thought is that I would have shot a series of images in different positions and perhaps come up with something a little more "attention getting" to the viewer. To me, that's just too much of an everyday type of pose for a subject that offers more potential. Definitely nothing "wrong" with the shot if that was what you wanted, though.
Note: Its so much easier to shoot images than to criticise them...