Lightroom’s Grid view shares many of the same keyboard shortcuts as other programs do for making selections including:
• Command (Mac) / Control (Win) -click (on the image’s thumbnail) to select multiple, discontiguous images in grid view.
• Shift -click to select a range of contiguous images.
• Command (Mac) / Control (Win) + A to Select All
• Command (Mac) / Control (Win) + D to Deselect All
In addition, when multiple images are selected in Lightroom, one of the images will be “more” selected than the others (and the grey frame around the “more” selected image will appear brighter/lighter than the others.) Lightroom has some additional shortcuts which make it easier to select/deselect multiple images:
• “/” (forward slash) deselects the active photo. If multiple photos are selected, the “most selected” image will be deselected.
• If multiple images are selected, clicking in the gray frame/border area around one of the selected images will deselect all images except the one clicked upon.
• Command (Mac) / Control (Win) + Shift + D selects all photos except the “most selected.