Use the image menu, accessed by right-clicking on any image, to select, deselect and remove images, and to view and/or modify image properties.
Select toggles image selection -- if the image is currently selected, this will read Deselect, not Select.
Remove removes the image from the composition (it does not delete the image file).
Color opens the color menu
Rotate/Flip opens the Rotate/Flip menu
Image Info opens the Image Information window.
Open in Editor loads the image into the image editor. Use this when you want to work with a larger copy of the image.