Well, I don't know about other places in the world, but here in the UK, they would be chocolate eggs, and therefore any size you like, pretty much.
To me the picture looked more along the lines of the more traditional painted Easter eggs.
Painted easter eggs were a common thing for me here in Canada, and are usually actual eggs. You'd punch a small hole in the bottom, drain the egg (makes a good scrambled egg breakfast to warmup), give it a quick rinse, and then you have a shell to paint. Some do it with hard boiled eggs but then if you want to peel/eat the egg you have to be a bit more careful with storage.
There is no shortage of chocolate easter eggs, of many different sizes, here as well... but they aren't usually 'painted' in the same sense. I guess foil wrapping would be the best you'd get.