The complete body is a midget on short stilts. (Stilts are from the knee down.)
The white binding around the waist is missing when they “reconnect” the lower half, as that section probably contains an electronic device that raises the one leg at a given time interval.
Notice how thick the upper half of the body is around the mid-section, as if he’s kneeling with his legs tucked up under the shirt.
When the legs are put back beside him on the table, the lower part of the leg is very thin compared to the “thigh” section and immediately when the upper half is in place, you see a “bump” at the knee section, as if a tiny foot (the toes) are sticking up.
The legs don’t curve downward when he’s on his back and, again, the shin section is very thin.
It’s at this point, that if you watch it very slowly, as they help him up from the table, you will see that the “knee” section is very visible and looks like a tiny pair of shoes, making the knee stick out prominently.
When he stands up and lifts his one leg, then the other to the side, it is done with the sort of little “kick” that a person with an artifical leg makes when they walk – an almost, but not quite natural flow. Watching it fast, you might miss that small movement. Notice the knees don’t bend when he jumps up and lands. Most people upon landing bend their knees for the impact – but not if they’re on short stilts like painters might use.
Finally, notice that his green shirt is now longer, coming down past the waist to hide the join (the part with the white binding was not brought over with the leg section, as the lower section had to be open to allow the legs to go into them quickly upon “rejoining” the two parts).