What I'm wondering is what is the resolution there, how many drones are there?
The image looks really well defined, but from what I could count it must be arround 200/250. If you consider Intel's current record is 2000, imagina what they could do with 10x more drones.
I know that some of this comments were from before the Dark Arts show, and so the opinions might have changed. But this has too many possibilities(and you can see that on the various Intel shows).
The problem of only being a recognizable from one side if you don't have enough drones to make it 3D, and even 2D images could be rotated.
The only real limiting factor is battery life, that from what I understand limits it for 10-15 minutes. But with 2000 drones you could decide between having: 10x longer shows of a 200 drone resolution, 10 200 drones drawings, or a really well defined 2000 drones image. And the technology will only improve.