Oh. I see how it is.
You just ruined the whole experience. Thank you SO much.
Found it completly by accident.
Viewing post in Baba Is You Levelpack: Vertigo jam comments
I can see how it may feel like a low blow to discover this gimmick on accident. My intention was to make the next level progressively more difficult to find but when I reached this puzzle I ran out of good ideas. The player is meant to note the cursor and look for level somewhere, but I'll admit this one could be a bit too concealed. At least it's better than hidden text.