I could be wrong, but it seems like there's a distinction between perceived sugar (amount of sugar in drink) as mentioned in the study and perceived sweetness (how sweet the drink tastes) which is what you're referring to.
You’re right. I tried to make my disclaimer thorough enough. :)
However, unless there’s something particular about the visual vs. the taste path, there should be some overlap. I think the anticipation (stress) is the part of this study with the most interesting implications to me.
