Ha I was falling for the optical illusion as well - I can see now they are on the outside
You'll want to keep an eye on these but these are not technically "cracks" they are seam separations. Do you have other physical cracks elsewhere?
I've seen some seam separations that look like they are all the way through, and inches long. So this example is not horrible, but it points to some potential fabrication issues
I have one that is about 18" from the top that goes from inside to about an 1/8 of an inch from the outside but it has not gotten any bigger either. It's more feathered that cracked, hard to see in pics.