She seemed like a normal 12 year old in that clip, but I remember a few years ago she was on Leno (she was maybe 8 or so) and she was incredibly mature and well spoken for someone that young. I, as a person who very much does not want kids, though that if I could be sure my kid was like that, I would have one.
No, she’s the Antichrist. 
I just watched the entire clip - and I think she was laughing because it sounded “weird” to say just “angel head”, as if the body were cut off…
But I have to admit, I watch the Ellen show often (one of the best daytime television shows in history) but missed this episode - and was very surprised to hear Ellen say, “My girlfriend is from Australia”…as I don’t believe I have ever heard her say “my girlfriend” before. Granted, it is certainly no surprise to anyone that Ellen is a Lesbian, but I never recall her just blurting out something like that - good for her!
And Dakota is no different that Drew Barrymore at that age - hopefully Dakota won’t have Drew’s problems as she grows up.
Actually, by the time Drew was Dakota’s age, she was already a full-blown alcoholic, so I think she’s doing pretty good.
Speaking of Drew & Dakota, here’s a priceless sketch from the recent SNL.