Just moved into a new office and saw this on the front of the dishwasher. It make's so much sense to indicate this in a shared environment where individuals aren't privy to the 'history' and timeline of an object. These 'current state' indicators help the extended group to understand a thing and are essential in social spaces. Yes, you could simply look inside at the contents but often this is unsatisfactory and creates more questions and doubt.It looked and felt like something that was stuck onto the dishwasher as an adaptation but it could also have been supplied by Electrolux.
OK, so this still doesn't completely work as there is no indication that the machine is running. The cludge is to put the slider inbetween clean and dirty.