Garfield Storytelling Devices 101: Something mysterious happens in Panel One as Character A sits at table with nonchalant expression. In Panel Two Character B, to whom something bizarre has happened, walks past silently. In Panel Three Character A explains what has occurred off-panel.
It's a useful structure, because it allows a medium-strength sight gag to be coupled with a semi-funny life-around-the-house-is-boring joke, and both are bolstered in the process. Though silly, I slightly prefer these strips to simple Garfield put-down gags, because they're harder to write, and gently nudge against the boundaries of the Garfield universe's reality. There's a quiet absurdity to the strip that actually augments the cynicism.
For example, today Garfield watches intently as in the adjacent room Jon opens the caraway seed canister (why?). Jon sneezes into the spice (why?), and promptly exits the room (why?). Garfield lets us know Jon has done this before. It's our job to understand: Jon goes out of his way to make sure it happens again.