Jim is really feeling the loss of Mike as a Friday afternoon companion, and it makes him more subdued than usual; but on the other hand he's always been able to pull it together for Laural (he worries about her more than he'd be willing to admit, worries because he likes her and her memories, to his mind, are worse to deal with than his own, worries because even discounting the memories she works too hard).
When she comes over, he's doing what he always does, now, after school, sitting in his living room with the classical music playing, reading with Sheila on the couch (which she has now taken as her own).