Here, they are being kings. They can both fit inside this cabinet, and that is their castle. Luke also made up a little catchy song that they sing while they march around the house. "I am the king, I am the king, I am the king of the jungle!" Just typing that makes the song get stuck in my head again.
Now here, your guess is as good as mine. I was cleaning the kitchen while they played in the back yard. I looked out the window to see them marching side by side across the yard, complete with their hats of choice, and one with a bat and one with a ratty old broom. This is where they were by the time I got outside to take a picture. These are definitely some of the best parts of my Mommy days!