1. A method performed by a data processing apparatus, the method comprising: receiving, in response to a search query for resources received from a user device, a set of search query suggestions, each search query suggestion being based on the search query and different from the search query; for each search query suggestion, receiving data identifying a respective set of images determined to be responsive to the search query suggestion; for each respective set of images, generating a representative image set depicting a subset of the respective set of images determined to be responsive to the search query suggestion; determining that a particular source of images determined to be responsive to one or more query suggestions has a diversity measure that meets a diversity threshold, where the diversity measure is a measure of a first number of images determined to be responsive to the query that are hosted by the particular source to a second number of images determined to be responsive to the query that are hosted by the particular source and other sources, and in response: generating a representative image set that depicts a subset of images hosted by the particular source; providing to the user device, in response the search query, a search results page resource, the search results page resource including instructions that cause the user device to render a search results page that includes: a set of search results that identify images that are determined to be responsive to the search query; for each search query suggestion, a search query suggestion grouping including: data describing the search query suggestion; data depicting the representative image set; and data depicting the representative image set that depicts a subset of images hosted by the particular source.