The comparison of the solid black square to famous art, and a description of the level of excitement about a brand "based on squares" where the brand is exactly only a square: those are the sarcastic components here.
These might even be interpreted as parody ("here is a great work of art by Uber, which is comparable in insight and execution to this work by a lesser known artist.")
These might even be interpreted as parody ("here is a great work of art by Uber, which is comparable in insight and execution to this work by a lesser known artist.")