If you draw a mustache on a drawing in an art gallery, you ruin the original for everyone else. If you take the drawing home, no one else has the original any more.

If I download, copy, or edit images sent to my computer, the original is still there.

The artist puts their art on the gallery with the intent that people will enter that gallery and look at it without touching. The image uploaders uploads the image with the intent that a copy (not the original) gets sent to our computers when we look at Google Reviews.