A printed origami diagram asks you to hold a three dimensional fold in your head while looking at a flat drawing of it. That works until the first reverse fold, and then the picture stops helping: you cannot see which layer goes where, and there is no way to look at the thing from the other side.
Origami folds your own paper in front of you. Pick a figure, put a picture, a color or a pattern on both sides of the sheet, and the preview folds that very sheet into the crane, the fox or the box. Every written step is a station in three dimensions: click one and the paper stands mid fold, ready to be turned and studied from any side, which is exactly the moment a printed diagram leaves you alone.
Because the paper is yours, it matters where things land. A region map shows which part of the sheet becomes the head, the wings or the lid, so a face ends up on the face and not on the underside of a flap.
When it looks right, one click lays print ready pages into your document: the folding sheet with cutting marks, the back of the sheet mirrored for duplex printing, and classic instruction pages with fold lines and arrows drawn from the same steps you just watched. Everything is computed in your browser.