Hello, I was wondering if anyone can identify the circled add-on in the image below.

And does anyone know if this helps in general as a learning tool to improve one's DPS parse?
Differences aside and yes this being a PC game in general, I still use a controller to game. It's my comfort zone.
Even though my character can hit like a bus and sustain crossing over the red (Aoe) , all this time playing I could not really figure out how to improve my parse.
So now I'm revisiting that and need all the help I can get.
ElderScrollsOnline Purchase History April 17, 2017 through May 30th 2022 (Crowns,Upgrades, ESO Plus) = $5,610.38