It's the "cross your arms" trick.
When you have a child who needs to be told something important, or reprimanded, especially one under say about 7, you have them cross their arms. It does a couple things:
-It makes them look at you and concentrate on what you are saying.
-It makes their mood, somehow-I don't know how- change. Usually they get a little giggly.
-It makes them look really really cute, which makes you really really less angry.
I've been doing this for years and it works wonders.
The other day, I was trying to get Andrew not to scream whenever his brother teased him. So I made him cross his arms and said, "Repeat after me. I, Andrew, will not scream bloody murder whenever my brother Matt teases me. I will go and get Mom instead, and she will help me."
He said, "Ok, Mom, I have one for you. Cross your arms and repeat after me. I, Mom, will buy her children a brand new X-Box 360."
(I said it, but inserted NOT of course.)