Why do we mark images as Photo's or Renders?

Why do we Makers, when uploading and providing details on models, have to check off a button asking if this is a photo or a render? I ask this because anyone viewing the image is not informed anywhere that the image is either a render or a photo!

I happen to add a caption to my images indicating either one, but the whole point of the buttons should surely be so that a viewer can tell immediately what he/she is looking at, correct?

You could ask the same question about the material specification.

Yes, quite right, I forgot about that.

I believe they are for future advancements, like searching for items that have been printed and in a certain material as an example of a possibility.

Okay, thanks... [steps into DeLorean and sets date for future] .... Yep, that's what they were needed for. And those 3D Printed flying skateboards were just great!