Apparently there's another circle of rainbow behind you, but you can't see it. They work it out from refraction angles.

The "little body" explanation is reasonable; a lot of letter-orders get reversed in Irish (bosca is box, srón is nose, the name Ó Hirile is translated to Hillery) so brog could be from the same root as corp-.

However, the -án suffix, if it doesn't denote 'a person with this property' (amadán = fool), usually means something big. Its opposite is -ín meaning small (as in smithereens). Just like Italian: violone = a big viola, violino = a little one.

Ah I get it. The -án denotes the person, the le- denotes the half size. What an amadán, not to see that earlier.