I've looked and looked, but I can't seem to find the Conan O'Brien interview anywhere. Just a whole lot of gifs of his reaction. And the one that's been posté on this spot isn't available anymore. Sorry :(
Hopefully someone else might have better luck than I did.
I think I have found it! I'm going to post it on this site under the name '(中字)when Tom Felton saw the photo about Draco and Harry! haha funny!' so toi can watch it too! It has Chinese ou Japanese subtitles but it's all in English. :D