Top back edge of my iPhone SE isn't well sealed and is collecting dust. Is this normal?

Hello,

So I bought my first iPhone ever, the iPhone SE (2022) from Amazon. The product was sold by Amazon on the Apple store page, so I assume it's original/official. I did do some authentication work on it, and it seems pretty legit.

However, I noticed that the top back edge of the phone isn't as well sealed as the other edges on the back. If you look closely, you'd see little black/grey dots inside the top edge.

I'm not sure if this is normal since this is my first iPhone. I'm thinking it's just dust getting in between, but the other edges look clean and well sealed that I cannot see any dust at all. The top edge seems to have a very thin gap.

I have few days to return the phone in case it turns out this is not normal.