If I use Google Translate to tell a waiter in France that I want something to eat, I also wouldn't understand the 'definition' of what Google Translate tells them. All I would know is that it might illicit the response that I am hoping for.

I feel like that's a pretty solid definition of how translation works, in general. If the animals are able to associate the different buttons with different outcomes, then I think it would still count as a rudimentary translation system.

Edit:

| It doesn't know the actual function or definition of the word.

Just wanted to clarify, the words are for the person to interpret... not the animal. I think the whole experiment makes a lot more sense if you think of it as the animal learning communication, as opposed to learning a language.