Confused about new buff/debuff display

I haven't yet seen this explained in the release notes. Previously, if a character had speed up, for example, that could get covered over by speed down. Only the speed down display, I assumed that was the debuff that had control. If that debuff got cleansed, the speed up could come back.

Now I see both. This can make it more clear that both are there, but do they now cancel each other out? Or if one is in effect and the other is being covered over, how I can I tell which one is dominate?