As far as I know, it’s because American eggs are required to be washed and sterilized whereas European eggs are the exact opposite, they are left unwashed. Both are perfectly fine, you just need to know to wash them before eating them in Europe. apparently you don’t need to wash them in Europe, just don’t eat the shell 🍳

the billboard is probably referring to growth hormones. some other companies do the same claim in their marketing.. but growth hormones have been banned in that industry in the u.s. since like the 1950s.