Because they know how cute their look there!
Just like this pretty applique by Cyncopia! And the nice font is also by Cyncopia.
When I was a child I did a guided tour of the tidal flats of the North Sea. At the end of it there was a customary baptism in a tidal gully. Every person got a nautical name – mine was „Lachmöve“ meaning laughing sea gull (which is called black-headed gull in English). And therefore it had to be part of my bag. Even though all stitched gulls are rather herring gulls.
I haven’t found an embroidery design showing a black-headed gull so far. If you know one, I would be happy if you give me a hint.