One of the joys of LR and non-destructive editing – the virtual copy. In Grid Mode, with your original selected, press the ‘ key while holding down the Ctl button. (Also in the Photo drop down menu.) Each time you create an additional VC (Virtual Copy). A virtual copy is just an additional database record pointing to the same original image. You can create a horizontal, vertical and B&W version of the original without having additional HD space taken up.