That single one flawed, yet harmless, element in an otherwise perfect design. Meaning that the designing process of the product was running smoothly until someone decided to have an engineering tic episode in the middle of it. A tourettes design does not bring down the overall performance, however, the consumer might not be able to quite let it go.
Said by that asian dude with a British accent about the Sony RX-1 compact camera in the popular photography webshow iDigitalRevTV/i.
"If only they didn't put this giant, glowing orange ring around the shaft of the lense. Everything else looks pretty nice; nice, clean lines, pretty minimal design. So the orange ring looks kind of like a tourettes design. Orange ring!"