Why stock-photo previews carry visible marks
A stock-photo watermark is usually a translucent logo, repeating text, or both, layered over a low-resolution preview. It is meant to remain visible across important parts of the image, so removing it by cropping or covering it may also damage the picture. The preview still lets a buyer judge the subject, lighting, and composition; it is simply less useful as a finished image.
The mark connects a preview to a license
The watermark separates browsing from use. A customer can find and compare images before paying, while the clean, high-resolution file is provided through a license. That license sets the terms for using the picture—such as where it may appear and for what purpose—rather than merely selling a watermark-free copy.
This matters because a photo can be reused in many contexts, from a personal project to a large commercial campaign. The price and permissions may vary accordingly. The visible mark helps protect the preview from being mistaken for an authorized final asset, while the licensing system gives photographers and image libraries a way to earn from use.
A tradeoff built into the preview
A watermark has to be conspicuous enough to discourage unauthorized use, but not so obstructive that shoppers cannot evaluate the image. Its placement is therefore part of the sales interface as well as a rights signal. The practical result is that a preview can answer “Is this the right picture?”—but the usable file arrives only with the permission attached.
