1. A method performed by an image search system of one or more computers, the method comprising: receiving a query from a client device; providing one or more image search results to the client device, each of the one or more image search results identifying a corresponding image resource and each of the one or more image search results including an image representation of the corresponding image resource; providing one or more related queries to the client device, the one or more related queries having been determined to be related to the query, wherein each of the one or more related queries includes a plurality of preview images, each preview image representing an image search result responsive to the related query; and providing instructions to the client device that when executed by the client device cause the client device to perform operations comprising: displaying the one or more image search results; displaying the one or more related queries; determining that a user has made a preliminary selection of a first related query; and in response to determining that the user has made the preliminary selection of the first related query, displaying a hovercard in proximity to the first related query, including displaying the plurality of preview images for the first related query within the hovercard.