All told, the robot is capable of replicating 2,000 body shapes. When a retailer signs up with Fits.me, they first send in their clothes. Each size is placed on the robot, which then cycles through all the body shapes it knows. (Think of the scene at the end of Terminator 2, when the T-1000 is being melted down.) While that's going on, a camera is taking pictures of each permutation. This photographic log is then stored in an online database. Once you go online and type your measurements into the retailer's site, it calls up the photo corresponding to your precise body type and clothing size.
Link via Popular Science | Photo: Fits.me
Actually you're right - for plus-sized people with extensive back bacon and ginormous thunder thighs, fitting service like www.myshape.com works probably better. For those people who instead of size recommendation would like to decide themselves which size fits them best (often people prefer tighter or looser fit), Fits.me's approach probably works better.