They were having a rollicking discussion when he suddenly veered off topic. This was made all the more obvious by scooting his chair over just a tish (titch, skosh, trifle) and announcing that he was now inside the Circle of Digression.
This is what happens when you watch a video on YouTube, watch a suggested video shown at the far right edge of the screen, and another, and another until you end up at a video that is completely different from what you originally watched.
I want to see some Pokemon game glitches. I'll check YouTube. (One hour passes) Why am I listening to "You Spin Me Round (Like a Record)"? YouTube digression, I guess.
They were having a rollicking discussion when he suddenly veered off topic. He made this all the more obvious by scooting his chair over just a titch and announcing that he was stepping into The Circle of Digression.