How is the lamb meat made in lamb gyros? I've been to several Middle Eastern inspired restaurants around where I live and in most of these restaurants, the customers are able to see into the kitchen as they prep our food. In the middle of the kitchen I normally see something like this: 



I asked the waitress what they were and she told us that the "blob" on the right is lamb. My friend then went ahead and order a lamb gyro platter. We watched as they carved thin slices off of the lamb. These slices look something like this:



My friend let me try a piece of the "lamb" meat but it didn't really taste like meat. It was tasty but the texture seemed too "smooth" to taste like meat. The texture almost reminded me of vegan meat substitute. Its texture was nothing like what ground beef felt like. How did they prepare the lamb that they got such a texture? And is this authentic or just an American bastardization of the authentic gyro meats?
For the times I've done gyros as such, you basically make a 'paste' out of it in the food processor.

Throw ground lamb in and give it a whirl, mix your spices and such in, put it on a spit, fridge to give a bit hard, and then on the spit.  It comes out with a texture like that.  That's how that kind is often done.

For 'proper' tasting meat (more like the one on the left), its alternating layers of razor thin meat and fat.