An electronic device displays one or more thumbnails. The device detects a first multi-contact gesture that includes movement of a first contact and a second contact; and, in response to detecting the first multi-contact gesture, the device displays content associated with a respective thumbnail and enlarges the content associated with the respective thumbnail to a respective enlarged size in accordance with the first multi-contact gesture. The device detects termination of the first multi-contact gesture; and, in response to detecting termination of the first multi-contact gesture: when a resizing metric based on the first multi-contact gesture is below a predefined threshold, the device ceases to display the content at the respective enlarged size; and, when the resizing metric based on the first multi-contact gesture is above the predefined threshold, the device displays the content on the display in a predefined arrangement.