For me, a radiator is an item of function, not of decoration or design. There are many new styles of hardware available (as you certainly know) that are a bit less frumpy than older styles. Even baseboards can be a bit less intrusive.

The beauty of a radiator is the heat it provides, not its appearance. I'd be concerned that the covers shown in the photos would restrict airflow and heat radiation and in doing so, would reduce the amount of heat the radiator provides to the room.

Take a look at this youtube video. The designer was faced with an apartment that had two HVAC units beneath a window. He proposed the construction of a cabinet that extended the full width of the wall. Perhaps you could use his approach; the right-hand side -- where there's no radiator -- could even be used for storage. The result might be an attractive piece of furniture rather than what's obviously a cover "disguising" a radiator.

That's a bizarre situation, wdccruise, a space smaller than a standard garage for 3 people to live in.

There was really no need to hide the radiator in that apartment, the bed is against it. Blocking it with the bed will surely limit the heat provided to that tiny space because of the airflow restriction it creates.

@Elmer J Fudd: "That's a bizarre situation, wdccruise..."

I was not suggesting anything other than a full-width cover the designer had drawn to hide the wall-mounted HVAC equipment, the concept of which I thought was superior to the radiator cover the OP photographed. The locations of the bed, desk and everything else in the drawing are irrelevant; I have no idea what other furniture the OP will place in his apartment or how it will be arranged.

Looking again at the OP's photo, a full-width cabinet built the depth of the window alcove might actually be a useful (for hiding the radiator and providing storage) and attractive piece of furniture. With a top the height of the window sill that extended outward and to end of the alcove, it could appear fully built-in.