The pop up tells you how much you affected your monster. If you hit him once but get 3 hits off then that?s great. It helps if you forget what number hit you were on. I believe it does something similar in regular game play. But It is a little confusing and misleading so I tend to ignore it during monster hunts
The pop up does not register the effect, just the number of hits. There is a lag that causes hits to be combined. I wish they would just get rid of it.