I really like the way you drew this. The expression on Thor's face is clearly shown, giving this picture emotion. It is really hard to pull off emotions in a picture, and you did a good job of showing it. You can definitely tell there is tension between them.
I also like the shading of the picture. You did just the right amount and did not go overboard like some people do. You can tell it is a drawing, but it doesn't look cartoon like. You can clearly see the facial features on both Thor and Loki, giving it a nice effect. I also like the way you did the hair. Every strand looks individually drawn, and you did a good job with the lighting as well.
Seriously, the hair! It looks gorgeous just like it does in the movies. (; I also really like their expressions. Not only because you captured Thor perfectly (I always imagine it being hard to draw someone looking angry), but also Loki because.. he does that thing again! Trying to look indifferent/mocking/amused and everything but you can see that.. there is more, you know? It kind of seems a bit sad to me how he is looking at Thor here. And I think it's perfect.
La cosa che mi stupisce di più di questo disegno (e degli altri simili a questo che hai fatto) è l'essere riuscita a rendere perfettamente la somiglianza con gli attori reali, seppur con una quantità non esagerata di linee ed aggiustamenti vari! Complimenti, non penso che potrei riuscirci mai io Posso chiedere con che materiali lo hai realizzato?