This type of singing is pretty common in the modern Rhythm and Blues genre, which is nothing like the Wilson Pickett, James Brown, Stevie Winwood R&B that we grew up with.
Uh, I didn't grow up with "Stevie Winwood". Maybe you meant "Steve Wonder"
. But in general, you are correct. The problem here is that what you are criticizing is a vocal STYLE which you either don't like, don't feel, or don't understand (or all three). The young lady clearly has near-perfect pitch, an incredible vocal range, flawless timing, and that most important quality for singing this type of song, SOUL.
As far as being too "emotive" or overdoing the "vocal gyrations", I'd rather HAVE the skills (with the ability to 'dial it back') than to not have it, producing endless streams of bland, soulless renditions of bland, soulless songs.
How quickly we forget that (our response to) music is a subjective thing shaped by culture, familiarity, and OUR OWN ABILITY TO FEEL EMOTION (remember the initial reaction to Elvis from the 'mainstream'). I was just listening to Christina Agulera's version of Leon Russel's "A song for you" with Herbie Hancock. Most would agree that she is an incredible singer (else Herbie wouldn't be working with her). There are enough 'vocal gyrations' there to create a tidal wave, but I think she captures the spirit of the song perfectly. Sure, 'different strokes for different folks', but for ME, I hesitate to criticize a vocal performance based on the singer's choice of a style I'm either not familiar with or not comfortable with. JMO.
chas