The red beacon allows you to move stacks of objects easily. Say you have a stack of objects. This stack can be there already, or you could create one by summoning boxes on top of each other. Start by marking the top box with your red beacon.
Now when you summon the highlighted cube, the red beacon that was attached to it will fall on the box right below it, automatically marking it red.
Now you can continue the cycle and summon the second box again. That in turn highlights the box under it.
When you summon the last box, since there are no boxes under it, the mark will remain on the box you just summoned.
This mechanic allows you transport structures quickly. Notice also how the boxes emerge aligned on the other end. Whenever you summon a box over another box, it automatically aligns. This enables you to create more stable structures.