1. A method, comprising: on a display, displaying a user interface comprising a catalog area, a collage mock-up area, and a mode select interface control operable to select an operational state of the user interface; displaying thumbnails of images in the catalog area; presenting a subset of the images in a layout over respective portions of the collage mock-up area, the collage mock-up area including a mock-up background object selectable to change the layout of the subset of the images; receiving a user input gesture on a target object displayed on the user interface, the user input gesture being one of multiple types of user input gestures, the target object being one of multiple object types; determining whether the user interface is in a first or a second operational state; in response to determining that the user interface is in the first operational state, performing a first action, selected from a first set of actions corresponding to the first operational state, based on (i) the type of the received user input gesture, and (ii) the object type of the target object; in response to determining that the user interface is in the second operational state, performing a second action, selected from a second set actions corresponding to the second operational state, based on (i) the type of the received user input gesture, and (ii) the object type of the target object; and in response to a point-and-click gesture on the mock-up background object, changing the layout from a current layout to a new layout for the subset of the images.