I debated putting a “MM-HMMM…” speech balloon pointing off-panel, down, in the last frame.  Decided that the core of the funny here is the haughty expression on this guy’s face, and I shouldn’t distract the reader’s eyes from the character’s.  The look on his face in the context of what he says is almost its own punchline echo.

For the record, I wrote this one forward, not backward.  The “hummer” punchline evolved naturally from the implications of the life of an itinerant piano tuner on the frontier, which I thought was a nice, funny/weird idea to build from.  Once I had the punch, I then went back to panel 1 and put in the setup line about his wanting to make his name a legend.

Also for the record, I go into this kind of detail because a large part of the feedback I get about these commentaries comes from readers who say they like it when I discuss my creative process.  So I’ll keep doing it.