This thought has been in my head for a long time…

As we all know, Ditto can transform in to any Pokémon that isn’t already a transformed Pokémon and in terms of the anime, Ditto keeps it’s same dot eyes instead of the original Pokémon it turned into’s eyes. This is done so:

1. It can reflect the games how its a 90% match but instead of not copying HP, it doesn’t copy a facial feature.

2. You can tell a Ditto from the actual Pokémon.

The question that I’ve wondered about is: What if a Smeargle or Mew used transform? How could you tell them apart? (In terms of the anime).