I think that last thing is a sink. In fact, it appears to be the only sink in the kitchen, picture trying to use that thing to wash some crud off a pan or something.
I'm fully convinced it's a house for sex parties. Glossy wipe down surfaces for added hygiene, plus the plastic covers on the seats and table, a pointless sink to rinse your dick in, the weird bedroom/toilet/utility room. It's high up on a hill so there's the potential for some al fresco fucking, a marque out front....I've clearly been thinking a lot about this
edit- I forgot about the glass gimp box under the stairs....