Sometimes a constitutional monarch finds a way of exercising power.
During a lecture on comparative constitutional politics at the Erasmus College of Law, (Rotterdam, the Netherlands) the professor mentioned that Queen Juliana of the Netherlands was his favorite monarch.
Before a bill could be sent to Parliament she insisted on reading it–often she would find mistakes and smilingly suggest that the MP do a little more homework before embarrassing himself.
Religiously zealous, and an adamant opponent to the death penalty, whenever a death warrant would be sent to her desk for signature, she would put it in a drawer. Due to royal rules of etiquette and decorum, nobody would confront her about it.
There was one breach of protocol when it came to a particularly vile Nazi war criminal facing execution. The Queen offered to abdicate to her daughter, the then-very unpopular Princess Beatrix.
The Parliament, people, and courts quickly dropped the issue.
Eventually the Parliament ended the death penalty mooting the issue.