What he describes here in the video is pretty much the way it works.
Keep in mind that a violin body is designed to resonate more by using a bow to vibrate the sound forward from the friction of the bow on the strings, whereas a uke or guitar body is designed more for plucking or strumming. The physics of this bears out.
Also, like Alan shows in the video in order to preserve the scale length and intonation, the violin bridge in the hybrid instrument has to be put in a suboptimal place on the body, where it is acutally the least wide, and will in fact vibrate the least. The result of this is a poor sounding instrument with shorter sustain than even a cheap $50 uke like the Makala Dolphin.
On a violin body, the bridge is supposed to be placed halfway or in the middle of the length of the F-holes, which would be about 2 inches back towards the tailpiece (from where he has it in order to keep intonation) in order to cause the violin body to properly resonate the sound forward in the most optimal way.
The Bridge placement problem gets worse if you put a concert or tenor neck on a violin body, i.e., NOT in the optimal location for good resonance of the body.
It certainly looks cool, but if sound and playability suffer too much, I personally would tire of trying to play such a hybrid instrument quite quickly.