What to do when science reporting fails even on Slashdot? The effect found in the study relates to performance on priming tasks. The abstract explicitly says: "has yet to investigate consequences for linguistic performance". Recognition tasks usually require the subject to hit the right button when recognizing a string of characters as a word or a non-word. A naming task requires the subject to point at or pronounce the proper name for an image, which is also influenced by preceding images or words. Performance is expressed either in error rates or in the (average) time it takes, and 100ms of difference is considered a pretty large effect. Anything larger is a bit suspect.
The classical priming task is showing people two words in a row, which are either related (bakery - bread) or unrelated (spider - bread). It turns out people recognize the second word faster when the first word is related. This effect is old, and pretty stable across studies and languages, and the same holds for naming. The effect also goes by the name of facilitation, and the opposite by interference or distraction. Now, it's pretty easy to consider showing a Chinese icon as just an example of interference. It can be considered to relate more to Chinese and therefore to "prime" Chinese language recognition and consequently interfere with English language recognition. That would explain the result in line with other priming experiments without implying anything about immersion, as immersion involves a lot more than an icon or a face, and as the interference effect decays over time. The effects of language acquisition in immersion or in your own ethnic group can be easily ascribed to the frequency of use, which has a much larger and self-sustaining effect.