Here is my opinion,
As far as "some people" are concerned, this should not be done. Here is my thoughts. Most of this "people" claim that the fish could not possibly be "happy" living under these conditions. I ask them and my self, why not? Fisrt, I can't speek for the fish. Second, I have NO WAY to ask them. But they do seem happy sometimes. I judge this by how active, healthy they are aswell as how they eat. I know for a fact that my Niger Trigger acts and eats different in the two tanks he has been in (10 QT, and 55 DT).
However, If I put myself in their shoes (ironic, they do nt wear shoes nor will they ever
) I can't help to feel trapped in this tank. Even if I had a huge mansion with everything I could possibly have (and I could not leave as I please), I would still feel trapped. Sure I would not be as sad as I would be in a cuban prisson. So I ask my self; If I am going to trap these fish and keep them in a tank, how can I possibly know how they feel in the tank that I do provide for them. I can't, that is untill I do and observe their behavior. If they are more intellegent and responsive, than single cell organisms. I should be able to assess "some what accurately" as to how they feel based on their bahavior. If they are not active or eating well, they must not feel well. If they are very active and eating, they must feel well enough.
Well just my thought.
As to the video. I do not know if this is a permanet housing for the fish or if they are there temporarely. Either way that it might be, they seem happy enough.