This is one of the best things I've seen in quite a while. I'm not a huge fan of Christian Slater and his overly jovial/casual style of acting, but Rami Malek easily makes up for that. Plus, this is one of the very few shows where the voice over works.

He looks like he wants to, but decides against it just before he smiles.
(I'm re-watching too. I love Fringe)

I think it reminds Peter of WHY he has fallen in love with Olivia. And the answer is: because she's awesome.