Ambassador sunglasses

So I just got a message on my Instagram profile on which I post some photos I take of nature and whatever I think looks nice. It's a pretty small profile with like 140 followers most of which are friends.

They are offering me some free sunglasses from Ambassador Sunglasses, not looking bad and their Instagram page looks pretty legit.

Now my question is, why me? I don't have that many followers to be a walking ad for them.