R&L's friendship illustration has a secret animation

And I can't, for the life of me, manage to trigger it again.
Triggered it once on mobile while on the way to work, and never managed to do it again.

It basically slowly zooms on R&L's faces and (i think?) they look at each other. I'm positive on the former part but I could be wrong on the latter.
Anyone else managed to trigger it or knows the conditions? I don't think it's an idle condition because I've been leaving the animation on for a while, and nothing happened.
It could just be a low chance when clicking/tapping on them, but I'm not sure.