1. A method of presenting images selected from an image store in response to a query, the method comprising: selecting images from the image store relating to the query; for respective selected images: computing a query relevance score relating to the query, and generating a first image instance scaled at a first zoom level that is proportional to the query relevance score; preparing an image instance set of scaled first image instances; presenting the image instance set; and upon detecting a user selection of a selected image instance in the image instance set: selecting a second zoom level for the selected image instance that is greater than the first image instance; requesting a differential image data set supplementing the first image instance at the first zoom level to a second image instance at the second zoom level; and upon receiving the differential image data set, presenting the second image instance comprising the first image instance supplemented with the differential image data set.