What does these icons mean?

The icon under Q and E. This is the first time I am seeing these icons

It is just the Elemental Overload buff indicator showing up on that skill slot — it marks that you’ve crit with that skill and have the EO bonus ready. Since Elemental Overload no longer shows as one big buff up top.

edit:
here’s the fixed image so others can see it and maybe add more info (or correct me if I’m wrong:)