So the pictures are accurate but it's a little confusing to piece together the apartment from the online listing.
The only full bathroom is downstairs on the street level and that is the only thing down there. Just an entrance way, a large full bathroom (which was very nice and spacious) and a metal spiral staircase to go up. Don't bring huge luggage or you'll have to drag it up!
The upstairs living space is fine. Not super fancy, but fine.
The ceiling of the sleeping loft is LOW. You cannot stand upright and there's no place to put a suitcase up there, so my daughter had to keep her suitcases on the floor in the main living area.
There is a very small toilet room in the main living area, and then a sink/shower combo (no toilet) off one of the main level bedrooms. We were just a family of four so we made due, but this could be a little weird if you were traveling with a large group or with friends.
It was warm while we were in Paris and AC worked very well. Plenty of dishes/etc. in the kitchen. Plenty of plugs / USB connections for phones, etc.
Location - there is massive construction on the street and it's blocked off. Kind of a pain with Ubers/cabs, etc.
There are prettier neighborhoods in Paris, but this was convenient to the Metro station and walkable to the Louvre, Les Halles, Tuilieres garden, Notre Dame, etc. Too far to walk to the Eiffel Tower.
We didn't use the washer/dryer, can't comment on it.
Overall - good space for Paris.