I bought one of these, some years ago, have used it many times and can say it really is a good and, for the money, cheap, easy to use projector. artograph also have the 'prism' projector, which is hugely expensive for what it is, as it works on the same principle as this tracer, in fact for the same price you are into digital all singing, dancing projectors. A reviewer said they have used it for photographs, I never have but would question whether the heat from the bulb would cause the photo to warp?, as the image is not that far from the light source. Basically what you have here is light and mirrors, simple but very effective way to transfer a image to another surface.
Size matters; the image needs to fit within the 5x5inch base, but don't let that fool you as it will enlarge greatly. The further away from the surface the larger the image and visa versa, focus is manual/turning the front focus ring, which has never fallen off during my use. Very easy to use. As another has pointed out, the tracer can get a little warm, and as it is an electric item then if a child is to use it an adult should be in charge, and for that reason I feel it should not be classed as a toy. It is lightweight/portable and I do not consider it flimsy.
If you want to transfer images to walls,canvas, paper... whatever, and do not want to pay the earth then this will do the job very well.