But, again, you are determining whether something is a sculpture or not based on your knowledge of what sculptures look like and/or where the object in question

But, again, you are determining whether something is a sculpture or not based on your knowledge of what sculptures look like and/or where the object in question is when you find it. Without that knowledge you are not able to make that determination. Without that knowledge you can only make much more basic statements, such as tell which one is heavier or larger, or what they're each made of. That's because those properties are intrinsic to the objects, unlike whether they're sculptures. You can't change those properties without changing something fundamental about the object.