W: nom nom
Pumi: ...
Wazowski: ?
P: The last bus has gone, there aren't any others today...
W: Hmm
W: Then you should just stay over
P: !
W & P: nom nom
Bus being crossed out probably means their master takes bus to go to work/business.
A picture of home being circled probably means their master staying home.
As someone else noted, it looks like the two are talking about how the "master" is staying at home, and isn't taking a bus to go to anywhere he needs to.