1. A method for previewing a visual representation of content, the method comprising: in a first allocated portion of a display screen, displaying multiple selected content items wherein the multiple selected content items represent respective multi-page documents; while displaying the multiple selected content items in the first allocated portion of the display screen, displaying thumbnail images of pages of each of the multi-page documents represented by the corresponding selected content items in a second allocated portion of the display screen wherein the thumbnail images are displayed side-by-side in a non-overlapping manner that allow preview of pages of each of the multi-page documents individually and concurrently; displaying multiple visual boundaries in the second allocated portion of the display screen to indicate multiple groupings of the thumbnail images to identify which grouping corresponds to which of the multiple selected content items; supporting at least one of: i) an operation of dragging and dropping a thumbnail image, in a first grouping of the groupings of thumbnail images corresponding to a first content item of the selected content items to a second grouping of the groupings of thumbnail images corresponding to a second content item of the selected content items in the second allocated portion of the display screen to modify contents of the first content item and the second content item, so that changes appear in the respective original multi-page document files associated with the first content item and the second content item when opened in a corresponding native application, the modified content of the multi-page document file associated with the first content item corresponding to the modified content associated with the first content item as arranged in the first grouping, the modified content of the multi-page document file associated with the second content item corresponding to the modified content associated with the second content item as arranged in the second grouping; and ii) an operation of copying a thumbnail image in a first grouping of the groupings of thumbnail images corresponding to a first content item of the selected content items to a second grouping of the groupings of thumbnail images corresponding to a second content item of the selected content items in the second allocated portion of the display screen to modify content of the second content item, so that changes appear in the original multi-page document file associated with the second content item when opened in a corresponding native application, the modified content of the multi-page document file associated with the second content item corresponding to the modified content associated with the second content item as arranged in the second grouping.