leetcode seems to agree with your definition [0]. the meme isn't to say that inverting a binary tree is particularly difficult - anyone familiar with coding challenges and trees could trivially produce a solution. the meme is more pointing out how ludicrous it is that senior/staff/principal interviews can hinge on these types of problems, despite the engineer proving their proficiency by doing something like running DOOM in typescript types or writing homebrew [1].
[0] https://leetcode.com/problems/invert-binary-tree/description...
[1] https://x.com/mxcl/status/608682016205344768