Good catch on the z thing, I’ll have to fix that up for the post jam patch!
Regarding three-by-five, I see where your head is at but the solution you wrote doesn’t work within the game’s rules. There’s a specific puzzle mechanic at play there that makes 3a-1c a valid rectangle but not 5a-3c. The game isn’t just about making the pictures match—it’s a puzzle to figure out how. I recommend replaying the second level and taking a look at what it does and doesn’t let you invert :)