If you're a Spanker, you're quite familiar with "The Look". It's the expression on her face right after you've spanked her for the very first time and you finally let her get up from being over your knees.
"The Look" is a mixture, a wide range of emotions. Surprise. Wonder. Shock (and probably a bit of awe, too). Indignation--although it's hard to pull off "indignant" right after you've been face down over a knee, bare bottom upturned and dancing under a descending palm, panties around your ankles and spending several minutes saying things like, "I'm sorry! I'm sorry!", or, "I'll be good, I promise!", or, "I'll never do it again!"
The chief emotion displayed on her face, though, is Disbelief. She really can't believe what just happened. Put into words, it's a look that says, "You...you.....you SPANKED me!?!"
It's going to take a little time to sink in, time for her to fully grasp what just happened and the implications it has for the future. The one thing she does know is that her world has just been (somewhat literally) turned upside down.....and things are never going to be the same again. And she's right. Her relationship with you isn't going to be the same ever again.
What she doesn't quite know yet? It's going to be better.