This place is in Gladwyne, PA, a high-falutin' suburb of Philly, where many well-off folk live as well as a few who are only moderately well-off.
I was just driving through. I saw it. I had to go around the block.
The phrase is not "objects d'art", it's "objets d'art". Otherwise it's only
half French.
Now, how many times per year do the store's owners get reminded of this error? Have they ever? Did they at some point decide just to leave it - and tell people they meant it to read that way?