Fwiw this is corporate propaganda, not state propaganda— it's a Carlsberg poster. Like Corona trying to sell beer on a certain image of Mexico, Carlsberg is trying to sell beer on a certain image of Denmark.

Copenhagen had lots of visible social issues.

Interesting. Coming from the U.S., the lack of visible social issues is one of the more surprising things. Compared to other places I've lived, like San Francisco and Atlanta, everything feels much safer and better run. I don't worry about walking home alone at 3am in Copenhagen the way I would even in nice parts of Atlanta. The public transit system is also much, much nicer than any other one I've used, generally being clean, on time, and running 24/7. I think the only place I've been that felt better-run and safer than Copenhagen was Zürich.

My friends all stayed at different AirBnBs across the city, and yet all of our apartments looked nearly identical: same floorboards, same IKEA furniture, even the exact same brand & size of TV.

I think this is more that AirBnB is only used by an narrow social segment. Residences I've been in vary from quasi-aristocratic decor (chandeliers, classical busts, etc., especially common in the inner city and Frederiksberg), to a minimalist "design apartment" style of all-white and geometric, and to a rustic look of dark wooden paneling and heavy dark-stained wooden furniture. The latter is what I think of as a "typical" Danish furnishing, but it's more common in the homes of older people.