1. A computer-implemented method for providing content, the method comprising: analyzing an image-based content item to determine information about a subject of the content item, wherein analyzing the content item includes performing image analysis on at least a portion of individual content items that includes an image; programmatically making one or more inferences about one or more of (i) a viewer or holder of the content item, or (ii) the subject of content item, including making the one or more inferences based at least in part on the determined information about the subject of the content item; wherein the one or more inferences exclude (a) information made explicit in the content item, and (b) information that is depicted with one or more foreground objects in the image of individual content items in the set so as to be recognizeable from performing recognition on the images of the individual content items; selecting a supplemental content to provide the viewer or the owner based on the one or more inferences.