Eroticism comes from the stimulation of the imagination!

Eroticism is an aesthetic judgment , conscious or not, linked to sexual attraction. In this sense , it provided much material for artistic performances. In art, eroticism is indeed a category or genre describing some suggestive performances, people (especially the nude, painting or photography) or scenes ( in literature and film ) 

Eroticism comes from the stimulation of the imagination, while not being unveiled at the sight : not only the desire to see what is not shown but more imagination magnifies what is not visible that is to say, makes the potentially even more beautiful in the mind of the observer. Indeed, the potentially “infinite” spring from the imagination no longer exists (or is severely decreased) when everything is exposed to view.