I wish I really understood it. LEGO is based in Denmark (sorry if I’m wrong here) so it is kind of a weird translation to English. My understanding is that an individual piece is a brick and the collective is LEGO. As far as “sands” is concerned, that is typically used for whole, or regions of, deserts. Once again, I really dislike the usage of LEGO as a collective noun in English. It might make sense in Dutch, but I have no clue how to read that language, let alone speak it.