Original drawing by St John of The Cross that Dali was inspired by.

 

A very interesting angle above and to the side makes it striking, memorable and fresh

Artistic licence has stretched to showing "the women" at the foot of the cross or the two thieves either side.  There is of course something very striking about the aloneness of a solitary image.

The black and white is softened and illuminated here by the use of yellow/gold.  Also elevated by it, to beyond the simplicity that black and white embody so well. Gold/yellow and purple are traditionally common within religious imagery eg icons for gold/yellow, purple for decor and vestments.