I found this fascinating! I have no ability to vet the paper for science I'm afraid, but on an intuitive level, and especially given all the different biological sensing and animal-cleverness results that have been reported in recent years, I would not be at all surprised if the 'vision' hypothesis holds in the end. Cuttlefish (maybe even perhaps their skin independently of the brain?) can do this type of pattern-sen…
They also can get by, for the same reason, with radically less of it, because the same machinery can worry at all stages of the problem, serially, one after another, not all at once as animals must.
Finally, because slow processing demands such a small fraction of their energy budget, they can afford to support a great deal more of it than animals can.
Plants can afford to be very, very intelligent. If we have not found examples of it, we might just not be looking correctly. What a plant could usefully do with intelligence might be decidedly non-obvious to such as ourselves, but it would be idiotic to conclude no such use is likely.
(Octopus, incidentally, are able to mimic colors their eyes are believed not equipped to perceive.)