Thought I'd elaborate on Ddlr's post.
It's actually just expressing a concept not a tehnique.
I'm not sure if they were thinking this far when demoing it, but the "prayer" position generally expresses balancing up and down forces, which you "compress" to the middle (the start of the prayer position).
All techniques you do regardless of shape are supposed to contain this. Its simple (actually not so simple hehe) efficient biomechanics.
It's the difference between using brute force and an unconnected body to do the job, vs a well connected/well trained body to generate extremely efficient force based on the bodies desire to remain in balance.
The guy over here in Japan at Aunkai does a similar demo. Only, he knocks you on your ass when you do it (regardless of the person's size) :)
The guy doing the demo sucked ass tho.
And I'll bet he would be knocked out by the "false" muay thai fighters you see in the ring.