The poor little thing is so tired, keeps stopping to catch it's breath, is breathing pretty fast. They work so hard, and if it could just get that foot on the edge of the egg shell...and push hard! Man, poor chickens, come into the world pushing, and the hens keep on pushing throughout their lives! Most of it anyway as long as they are laying.
Front chick seems like it hasn't zipped enough, and is trying to push open. I haven't watched a TON of eggs hatch, but the ones I did see, it seems like they zipped more instead of trying to HULK SMASH out of the egg.