The Mirror allows you to create simultaneously reflected on two sides or on all axes at once. Here’s how this works.

https://www.youtube.com/watch?v=49uS75hSxi4

In this lesson:

Activate the Mirror

When you have a primitive selected, it will open up it’s properties menu at the right. Scrolling down a little bit, there’s the “Mirror mode” where you can activate the mirror on all axes.

How the Mirror works

Once the Mirror is activated. You simply drag your primitive to the right to see it reflected on the other side. Dragging it to the left will make the shape fade in the center of the scene. The Mirror will always be in the center of the scene unless we create a union which will then dictate a new center of the mirror.