I agree that that "other study" looks at Chinese rather than Japanese students, and it's high school + grad students rather than undergrads; but, still, let's compare what Brooks says with the reality.
Brooks: "If you show an American an image of a fish tank, the American will usually describe the biggest fish in the tank and what it is doing. If you ask a Chinese person to describe a fish tank, the Chinese will usually describe the context in which the fish swim."
The study: (1) Not a real fish tank but short animated vignettes. (2) All the fish were the same size, so anything Brooks says about "the biggest fish" can't possibly apply. (3) The only "context within which the fish swim" was provided by the other fish. (4) The experimental subjects were not "asked to describe a fish tank". They were asked specific questions like "To what extent do the blue fish's movements seem influenced by the other fish?". (5) The differences were not about whether experimental subjects described one particular fish or the context in which the fish swim. (6) The differences found were far smaller than "Americans usually do X, Chinese people usually do Y".
Here's the biggest effect they found: they asked "To what extent do the blue fish's movements seem influenced by internal factors?" and took answers on a scale from 1 to 5: 1 = hardly at all, 2 = slightly, 3 = moderately, 4 = greatly, 5 = almost entirely. In one category of cartoons, which the experimenters term "compulsion", American high-schoolers gave an average answer of 3.17 and Chinese high-schoolers an average answer of 2.56. Second-biggest effect: same cartoons, but now asking "To what extent do the blue fish's movements seem influenced by the other fish?". American: 3.27. Chinese: 3.61.
These, I repeat, were much the largest effects found by the study among the several cases into which they subdivided their findings. For grad students looking at the same category of cartoons, the answers were 3.07 for the Americans and 3.00 for the Chinese (first question) and 3.77/3.82 (second question). Most of the differences they found were of this sort of size, and some of them were in the "wrong" direction.
If you think this study supports Brooks's statement about what happens when Chinese and American people look at fish tanks ... well, I really don't know what to say. It's not even addressing the right question to support (or refute) Brooks's statement, and in any case the results are far weaker than Brooks implies.