More semantics: I think the question of whether or not Payne is mocking his character is a red herring. I don't think it matters what Payne
is laughing at but what the film invites us
to laugh at (and how we respond). Take, for example, the fact that the freeze frames of Tracy always show her at her most unflattering (Junior provides a sample screenshot
above). What motivates this choice? Is it just, "Hahaha, this girl looks dumb and ugly like this!"? Or is it supposed to represent, subjectively, the way McAlister sees Tracy (making his pettiness the target of the joke)? Both options seem problematic to me (there are probably other options): the first because "look how ugly she looks" isn't my kind of humor, so I personally would chalk that up to a joke that misses and even insults; the second because I don't think McAlister's seeing her like that is consistent with the rest of the film. I think he's threatened by her external beauty and inner poise, resentful of her sexual attractiveness that led to Dave getting fired but also inspired by that attractiveness to pursue a substitute sexual fantasy.
[I could argue the other side of this, but I'm tired and there are other people left to chime in.]