I have been doing jars for far too long. Years.. I used to travel a lot, and it was inconspicuous all while producing without having to spawn it. It’s hard to tell from just one side but I would be willing to bet that jar is fully colonized. As the mycelium colonize’s the spawn it shrinks. Some more than others. I believe what you’re seeing is the top vermiculite layer being shifted. falling to the sides.
Based off of my experience I would watch those pins. Once they are full grown, birth the jar. If it’s not fully colonized, it certainly will be by then.
Thank you for your input Cybele! I was starting to wonder that myself but this being my first time, I was unsure when to birth. The jar I showed is actually one of 12 that are the same age, but each jar has decided to colonize at different speeds for some reason. I will birth any jar that makes a full grown pin!