Nemo determined to fit through one of the bottle openings:
Look at that foot shoving off under Iggy's foot.
Pushing off Iggy might be better leverage.
Determination from both sides before exiting left over the stuffed animal turtle which is the side entrance with plenty of clearance.
Nemo typically does this when he comes to any enclosure. "The grass is always greener..." must be his motto. After taking the photos, I wanted to make sure he was not in distress. I tapped my fingers to the left making a clicking sound I use for his attention. He reluctantly gave up going through the bottle opening and practically jumped over the turtle to exit. He knew exactly how to get out! And was probably annoyed I ruined his fun. Silly me.