When they can, birds like to dive straight down on top of a fish in part, because in that position, the fish is mostly where it seems. At an angle, the fish is not where it seems because light bends when it enters the water. So, when diving at an angle, fish-eating birds like Kingfishers and Ospreys understand that they need to adjust their perceptions.
I attended a challenging two-day dance workshop where we were asked to choose our dance partners based on different themes. For the first dance, we picked a person who we were afraid of, then danced with them for an hour. Then we chose another partner based on who we thought we would be the least happy with, and so on. I was surprised that my original perception of each person was completely off-base. It was another learning to hold my beliefs and perceptions lightly because the fish is not usually where it seems.