1. A computer-implemented method comprising: receiving, at a computing device in a physical environment, an image of a visitor to the physical environment, a visitor portion of the image being distinct from an environment portion of the image; detecting, by the computing device, a shape in the visitor portion of the image using an automatic shape detection technique; defining, by the computing device, an approximate boundary of the shape using a mask; calculating, by the computing device, an attribute for an area of the image within the mask; identifying, by the computing device, electronic content based on the attribute for the area of the image within the mask; and providing the identified electronic content for display in the physical environment.