I do this with my dog, our couch is against a window that overlooks my building's courtyard so she's always watching people come and go. If I'm waiting for food or something I'll watch with her, she seems to really enjoy it.
Random toilet thought: I wonder if doing that with your cat actually builds some familial bond with them different from the habituated human that they may perceive us to be. Specifically an actually pride member coparticipating in hunting.
To be honest I reckon they probably think we're cramping their style and would prefer that we simply fuck off and get some catnip.