Mines two and it still looks like that. I was told it's to make sure that they have that skin there to grow into when they're older. If it's not left on like that they'll have a lot of pain when their bodies grow from the lack of skin and it being too stretched. It's completely normal.

He should grow into it but ask Dr at next appointment if it concerns u

He’ll grow into it. They have to leave some skin for growing. At least that’s what I was told