Whenever the active corners are enabled in System Settings, the user can drag their cursor to the corners of the screen and trigger some actions. There is a blue graphic that is used to show that your corner is now active. The graphic shows a few too many pixels before reaching the corner of the screen. I propose that it shows when the cursor actually hits the corner.
To me, having this ahead does not help the end goal. It has made me desist from nearing the corner screen. At times it can be misunderstood as a desktop widget and covers other elements on the screen.
From the screenshot you see that the graphic shows too early. The cursor is not yet at the screen corner.