That's the exact opposite of lossless compression. It is a creative way to implement lossy compression for a limited subset of images, though.
It's concerning because it either means they don't actually know what lossless compression is and believe they are doing it - or they are engaging in borderline fraudulent marketing.
Given they actually built an impressive product for subset of images it works with, I'm going to assume it isn't the former.
I can see their reasoning: "it doesn't appear to be any lower in quality because our brain focuses on the face to determine it, so you get the same effect as lossless compression ergo: lossless compression" - but that still feels rather slimy to me and is a great example of marketing trying to repurpose actual technical terms to fit their product.
Where? (I probably just missed it but I don't see it.)