There's something off-putting about this soldier and the way he leans in as if saying something in Christ's ear. His expression is difficult to read. Is he worried or smug perhaps?
His outfit's not easy to interpret either. The strange hat decorated with the oak leaves and an acorn are in contrast to the spiked dog-collar around his neck. These spikes along with the thorns above Jesus' head appear terrifyingly sharp, so close to neck and head.
This soldier's brutal armour-clad hand clasps the thorns above Jesus' bare head; its circular form reminiscent of a halo.
Bosch's handling of paint is extraordinarily skilful; working wet-in-wet for the armour and then dragging or feathering the pigment with dry brushes.
Christ looks out at us directly. It's unnerving. His expression is calm despite the mockery and torture he has to endure.
The surrounding figures, crammed into the frame, all look at Jesus and our eyes follow.