Two hussars sit perched on horses, dressed in extravagant ceremonial wear, each holding a sabre in their right hand, reigns to the horse in their left.
There are professional riders at a ceremony.
Being dressed in ceremonial wear does not necessarily imply that they are at a ceremony.
Not all riders are professional riders.
The hussars could be wearing ceremonial wear without being at a ceremony. For example, they could be at a dress rehearsal.