1. A computer-implemented method comprising: receiving an instruction to display, within a social-network interface, an image-stack viewer that comprises a frame, wherein the social-media interface is associated with a first account on a social network; determining respective locations of one or more tags in one or more images from an image stack, wherein the image stack comprises a plurality of images of a scene: using one or more image characteristics at the respective locations of the one or more tags in the one or more images in two or more images from the stack as a basis for selecting a first image from the image stack, wherein at least one tag is associated with a second account on the social network; displaying the first image in the frame; receiving interaction data that corresponds to an interaction with the image-stack viewer; determining a region of interest (ROI) in the frame, wherein the ROI corresponds to the interaction, and wherein the ROI in the frame maps to a corresponding ROI in each image from the stack; using one or more image characteristics of the ROI in two or more images from the stack as a basis for selecting a second image from the stack, wherein the one or more image characteristics comprise at least one exposure characteristic; and causing the graphic display to display the second image in the frame of the image-stack viewer.