It also doesn't help she's still talking with a Japanese audience in mind. I know that way of speaking from when I teach
May J talks like that as well when she speaks English on J-Melo I noticed. For someone who has not spoken much English in five years or so she's got a pretty good grasp of it.
As a side note you can't really compare singing pronunciation to talking pronunciation. Singing is all about mimicry (As I'm sure anyone whose done a choir song in another language can testify) while talking is much less focused and practiced. My closest Japanese friend can sing with absolute perfect pronunciation, but her talking is very much heavily accented. Japanese speakers especially suffer because of Waseigo, or the words they have adapted from English and other languages, but written in katakana so that they lose their original pronunciation. I have to fight against that every day I teach ~_~ It's why the 5 year olds I work with sound much better as well since they have yet to become stubborn on the pronunciations. But I heavily digress
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