Is my bird too fat or too thin?

Is my bird too fat or too thin?
The easiest way to feel and observe a bird.
A very easy way with not clever birds is to look at the wings.
These cross each other slightly at the end.
If this becomes quite a distance, then the bird is thin.. if they don't cross, then the bird is too fat
Then the breastbone.. does it feel like a sharp edge? If so, the bird is too thin.. if you don't feel it, the bird is too fat.