That is cool but I wonder how it differs much from training a dog to bark three times with the prompt of the spoken of visual number three... or other numbers. While not verbal a horse can be taught to 'tap' of its hoof to a number prompt. While I haven't read anything on this I'd be amazed if a dolphin could not do it.
Bottom line is that we tend to not give enough credit to what some animals can do in relation to some sort of intelligence simply due to it being a different form than our own. Birds are a really good example of this as it has been discovered that some species of birds are on a par as to 'intelligence as dogs and cats.
This part is just speculation but studies show that humans use a small portion of their brain and that many animals can't have intelligence due to the smaller brain size. What if some animals use all of theirs? Seems to me that it would lessen the apparent size difference of the brain. Going with intelligence being a factor in intelligence than, by that logic, whales should be more intelligent than humans and, sometimes, I wonder if that just may not be true...
As Spok said in Star Trek 4... "There are other species on earth. Only human arrogance would assume the signal must be meant for mankind.".