The Invert Rectangle effect allows you to highlight an object in the video by setting out an rectangular-shaped "window" which remains free of color coverage.
In the Properties Window you can change the effect properties. The properties of the Invert Rectangle effect available for setting are brush type and other properties depending on the chosen brush type. There are the following brush types in the dropdownlist: solid, gradient, hatch, texture. See the description of all the types here.
It's also possible to change the location and size of the inverted rectangle like while applying the ellipse effect. Click here to learn more about it.
On the figures below you can see the video picture before and after applying the Invert Rectangle effect:
Before applying the Invert Rectangle effect
After applying the Invert Rectangle effect