Jace isn't the type of guy that is going to sit around and let other people dictate how things should go. It looks like he's going to take things into his own hands.
Meliorn seems to be taking a peek at his one-time love, Izzy. Either that or he's planning his escape route. I bet he wishes he never got involved with the seductive and beautiful Isabelle Lightwood.
Alec is probably tired of chasing Clary all around and is probably relieved that a member of the Clave is at the Institute. Lydia sure looks like she means business.