Question on Season 8 Episode 8

Hi everyone,

In this episode Bubbles builds the super-duper-industrial-Bubbles-Honey-Oil-inator. Prior to this, the Boys hugged it out and Bubbles was making train sounds.

Why was he doing it? Was this his was of saying that he enjoyed the moment and because he has of course an affinity for trains?

Thanks for your feedback in advance!

Cheers!