I think the Longvida is a micro encapsulation of the curcumin in tiny beads (like nano technology). They probably coat the beads with the lecithin and if small enough these can cross the GI membrane into the blood.
This is from Wiki on how the product was developed:
from http://en.wikipedia.org/wiki/Curcumin
Naturally they have a patent on it and are not going to reveal in emails exactly how they accomplish the improved absorption.
I think the second patent in the quote is the Curcugel product.

Nano technology is the up and coming thing for drug delivery too..especially chemo, and other target organs etc.

Here is an example of liposomal curcumin, which uses similar ideas and is a liquid.

http://www.nanoliposomals.com/Liposomal_CURCUMIN.html

Liposomes are tiny... and suspended in a base. They use various liposomes now in cosmetics for the skin...most of the high end cosmetics have GLA or other fatty acids in liposome delivery.