Tae Moriyama [author of Kanji Connections] gives the explanation of bi 美 = beauty. The way its cut in modern times it is indeed Tae’s explanation which looks factual. Its Big大+sheep羊. To a farmer’s eye the sheep is beautiful when its bigger.
But me-thinks, instead of Big+ sheep its Heaven天+sheep羊. Sheeps are ugly, only if they were to come from heaven they would be beautiful.
The ancient Japanese people knew the meaning of “beauty and symmetry” the kanji for beauty is very symmetric: 美 ..