There's a limit to how high you can pile a narrow line of a puree. Mashed potatoes will probably do a bit better, but you're still not going to get any "true"

There's a limit to how high you can pile a narrow line of a puree. Mashed potatoes will probably do a bit better, but you're still not going to get any "true" 3D design out of something that isn't solid. There's also the time factor. Printing out a single layer of a sauce/puree in a fancy pattern is a lot faster than making a complex multi-layered shape. At any rate, there are certainly 3D desserts and showpieces, and there have been for awhile. The neat part of this is that it's being used for more than just sugar and chocolate.