In this video, the prototype solar tower works a little differently. While it still collects the solar rays to send to a single point, the target is located in the underside of the tower head where there are more mirrors that collect a tighter beam to focus down to the ground where the heat engine is located.
The advantage of this is that you are able transmit a lower energy density through the air to the tower head, which should result in a lot less bird deaths from them inadvertently flying into the beams. The 2nd advantage is that you can leave the heat engine on the ground level which means you do not have to carefully design to minimize its weight to go on the tower.
I wonder if we will see more of these soon?