1. A computer-implemented method for displaying a portion of a higher-resolution image in the context of a lower-resolution image, wherein one or more processors are programmed to perform the steps comprising: receiving a user indication of a position on a display that corresponds to a point in a lower-resolution image that is displayed on the display, wherein the lower-resolution image comprises an image in a first resolution; sending a request to a server over a network for a higher-resolution image that corresponds to the lower-resolution image; receiving the higher-resolution image from the server over the network, wherein the higher-resolution image comprises the image in a second resolution that is higher than the first resolution; receiving a user request to view a portion of the higher-resolution image in a virtual lens overlaid on the lower-resolution image; displaying the portion of the higher-resolution image on the display in the virtual lens overlaid on the lower-resolution image, wherein the portion of the higher-resolution image comprises an area that includes a point in the higher-resolution image that matches the point in the lower-resolution image; tracking changes to the user-indicated position on the display; and whenever the user-indicated position on the display changes, updating the portion of the higher-resolution image displayed by the virtual lens and positioning the virtual lens with respect to the lower-resolution image, such that, at the user-indicated position on the display, a point in the portion of the higher-resolution image displayed in the virtual lens matches a point in the underlying lower-resolution image.