Here's Little Bitty standing on his stool (potty seat with the lid down) next to the window. I love the expression on his face in the reflection.
Usually he prefers the windowsill, he's seen his brothers do it plenty of times. I snapped his picture and realized how similar it was to a picture of my twins taken when they were younger (they were about 18 mos old in the picture below). Here are both pictures:
For a great post on not only standing but dancing on windowsills, visit Rhema's Hope.