How to fish for Annabella's Request in Crimson Desert

Puzzling out how to fish for Annabella's Request in Crimson Desert is rather tough, especially as the game doesn't explain the key principles of fishing in its help section (how helpful). It's easy enough to head to the spot she highlights, take out the rod, and cast the line, but how the actual catching of the fish works is a mystery you'll have to work out yourself.

Or not, because I already worked it out and have detailed it below. The key principle is that you need time when you reel, similar to fishing in some other games.