This is a piece of Fan art created with the Sims 3. Harry is the one with an observant look on his face as Hermione casts a spell. It is not of any specific scene. Please note that in this fic, they are both in Ravenclaw. It is a really good fic, at hpmor.com, Petunia married a kind professor, and they treated Harry like their own, rather than something they scraped from the bottom of their shoe. Now Harry's a rationalist, and you don't want curse him for his "Gryffindorish" choices. Do read it.