Why does orpheus look back?

Orpheus looks back at Eurydice as he is leading her out of the Underworld, compelled by doubt and longing. Despite being warned not to turn around until they reach the surface, his love and anxiety overwhelm him, leading him to seek reassurance that she is truly following him. This moment of hesitation ultimately results in Eurydice being lost to him forever, symbolizing the fragility of love and trust.