Visual reasoning is not required to follow an algorithm that was laid out. The fact that the model can't execute an algorithm it was provided proves that it is not able to do deductive synbolic reasoning in general, since that is all that would have been required required.

I would agree with you if this were about inventing the algorithm for itself - it may well be that you'd need some amount of visual reasoning to come up with it. But that's not what the GP (or the paper) were talking about.