Is it incorrect to say, "they look better in person than they do in pictures" when referring to a thing rather than a person? Would I have to say, "they look better up close than they do in pictures?" Or maybe even, "they look better in real life than they do in pictures?"
I'd go for your last option.
If you are talking about a thing, you shouldn't really say "in person (or in the flesh")
If you say "close up" you could be close up to a photo or picture of the item.
Hence the last option.
Hope this helps