From Latin 'displicare' (to unfold) — to display is to unfold what was hidden so it can be seen. Doublet of 'deploy.'
To put something in a prominent place so that it may be readily seen; a performance or show intended to entertain; an electronic device for visual presentation of data.
From Anglo-Norman 'despleier' (to unfold, to spread out, to deploy), from Old French 'desploier,' from Latin 'displicāre' (to scatter, to unfold, to spread apart), from 'dis-' (apart, away) + 'plicāre' (to fold, to lay flat), from PIE *pleḱ- (to plait, to fold). To display is literally 'to un-fold' — to spread out what was folded or rolled up so that it can be seen. The military sense of deploying troops (spreading them out across a battlefield) and the modern sense of public exhibition both preserve this core spatial meaning: you display something by unfolding it for
English 'display' and 'deploy' are etymological doublets — both come from Latin 'displicāre' (to unfold), but through different French routes. 'Display' came through Anglo-Norman 'despleier' and kept the sense of 'unfolding for show,' while 'deploy' came through later French 'déployer' and took on the military sense of 'unfolding' troops from a column into a line of battle.