I think he is missing a zero. 17 sqft is a mini-closet, not a mini-apartment. 170 sqft would still be pretty small, but doable.
It’s a mini apartment with huge quotation marks around it. One 9 square meter living room (with cupboard, sofa, table), one 8 square meter bedroom, including a shower. Toilet and tiny kitchen niche in the tiny, 1 meter wide hall not included (for whatever reason) in the 17 square meters.
I still think the 270 Euro/month are pretty expensive for what it is, but luckily I only have to live there for four months (and in the summer, so I’m not going to be in there all the time and will rather try to enjoy the city).