This is Aaron David Fairbanks Bongard problem problem n. 70. Try to write your solution (with a spoiler if you want). I'll give my solution tomorrow.
For more info about Bongard problems in general take a look at my first messages:
https://mathstodon.xyz/@leonardom/116110015131667314
https://mathstodon.xyz/@leonardom/116110093951382315
