Just recently I was asked to duplicate a digital rendering using the actual product. Digital renderings have none of the limitations imposed by the physics of camera optics. Perspective, distortion, color shift and annoying little product defects can all be eliminated with a digital rendering. The resulting image becomes an unreal,representation of the product. The rendering displayed here uses a logo not found on the actual bottle casting.
Sometimes, as in this example of a hand soap dispenser, the consumer may not be as sensitive to the appearance of the product as say a decor object where the actual object will be on display. Manufacturers are quick to produce these "renderings" as they are relatively quick, cheap to produce from product mock-ups and show their products without defect.
Which you as a seller choose to use will depend on your clientele and products. As a note, you will never see Tiffany's use anything but actual photos in their public facing advertising, highly edited, but still the actual product offered.
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