This is trending somewhat on various Japanese art sites and social media, with people drawing art parodying the pose.

It's usually tagged as 江ノ電自転車ニキ (Enoden Bicycle [A]niki) on those sites. Currently I've tagged the posts we have uploaded with Enoden bicycle bro (meme). Though maybe we should change this to a char tag instead and tag Enoden Bicycle Bro together with real life for such examples?

It's not altogether unprecedented to tag a "character" when another character is pantomiming the former and/or mimicking their lines, even when they aren't "cosplaying" per se.