It has an absolute fuckton of gear inside of it, however. The camera equipment alone is quite a volume, to say nothing of all of the racks of stuff for experiments, exercise stuff, life support and water recycling, power storage, etc.
Yes, the photo in the article looks very cramped. Probably the same tightness in all other areas of the station, with a few exceptions. I wonder if they make any changes to free space from time to time?