I'm unsure. It's a small museum, so small in fact that I'd never heard of it until this discovery. (BTW, obviously this isn't a "new" painting, rather the rediscovery of an old painting. Not that surprising considering the fact tha Van Gogh didn't get famous until after he died...)
After looking at the picture again (of the museum), I think it's in the lighting - plus there's a slight frog-eye effect.