Yeah, I get what you're saying. I think it's just the fact of human interaction - a safe pause amidst the terror. Plus, especially viewing it today, it's a down home, warming portrayal of a what used to be standard protocol at a service station. The pump man would top you off and check under the hood. Classic Americana, and I think that resonates with people.
It's genius in execution - just enough of a sigh of relief before the rig lumbers into the same station, the attendant oblivious to the truck's intentions.

I like that part and guess it is relaxing. I like the sound of the spray on the screen lol and just feels like a relaxing scene.