Dean’s like, "What the fuck is going on? Where am I? Oh no, all these feeling are back…" . He’s confused and sad, like he’s back in his misery again. And then it’s like all memories comes chrashing in back to him. The he is like ‘omg, it can’t be real.' then he looks at Sam with some kind of anger.
Can you see how his eyes are glazing in the last picture? It’s like “I’m gonna end you for this”. They are glazing dangeroulsy.