Some things need to be shown as objects before anyone believes in them. A digital product especially: an ebook, a course, a template pack. They have no physical form at all, and a picture of a book is the shorthand our brains accept.
The Mockup Generator takes the design you have open and places it onto a rendered object, lit as if it were photographed in a studio. Ebooks, software boxes, screens and a set of other classics, each with the shading and perspective that make artwork look applied rather than pasted.
Two things decide whether a mockup works, and both are worth saying out loud. Match the light: if the scene is lit from the left, your artwork should not carry a shadow falling left. And use them sparingly, because a page where every product is the same rendered box reads as a template gallery rather than a shop.
For heavier work there is a separate 3D Mockup Studio extension with a much larger catalogue and per-surface artwork. This built-in one covers the everyday cases, which is most of them.
