I think in English this sentence would only be used in speaking about someone's occupation or the application of a skill, so that 'art' is acting as a synonym for 'art-form' or 'knack'. Is this the sense if this sentence in Swedish? Or is this a grammatically correct way to point to a concrete object and describe it as a piece of art?
It's the same as in English. Otherwise you'd say:
Det är konst = It is art
Det är ett konstverk = It is a piece of art
It actually did mean 'artful' just a couple of hundred years ago, but most Swedes don't know this. The first time I found out was when I read about some painting from maybe 17th century that it was painted med egen konstig hand which made me laugh very hard.
There's an old anecdote (more legend than fact, unfortunately) that when King Charles II first saw the new St Paul's Cathedral in London, he described it as "artificial, pompous and awful" (or, as a modern English speaker would say, a work of art, stately and awe-inspiring). http://quoteinvestigator.com/2012/10/31/st-pauls-cathedral/
Interesting indeed how word meaning shifts over short spaces of time from generation to generation.
I realised they must have been related when i was in the k-o-n part of the dictionary. Made me laugh when I had images of Swedes viewing anything art related as strange. "what the hell is she doing. It has no purpose. Strange".
For those of you, who also learn German: It is the same use in German as in Swedish., e.g.:
"Es ist eine Kunst, Schwedisch zu sprechen." Det är en konst att prata svenska. (förrhoppingsvis rätt översättat)
Correctly translated, but the past participle of "översätta" is "översatt". ;)
'A piece of art' is ett konstverk, but that's not what the sentence is about. There are some good examples in takver:s comment and other comments on this page how the sentence could be used.