In QED by Richard Feynman, page 23 in the footnote; Feynman mentions that partial reflection is not an easy problem to tackle when we consider light as a particle and stated:
Those who believed that light was waves never had to wrestle with it.
If it was a mechanical wave I'd have tried to think about it as a typical collision problem with the wave losing some of its momentum causing the material to vibrate and some part of it gets reflected but what about electromagnetic waves?
Can you conceptually tell me why, if I consider light as a wave, partial reflection can be readily explained?
P.S I am not interested in how to calculate the probability of the reflection, the book goes through that, I just want to know why if I consider the light as a wave this won't be an issue.