It's not her best, but as a portrait you get a much better sense of style, attitude and energy from it. There's presence there, and if you didn't know who it was...I feel you'd be asking who that girl is. I dare say there are stronger shots from this shoot.
Katy's is dull. I feel we've seen it countless times already. Expressionless with predictable finger-at-mouth popstar cliche. If they were going for 90s styling, they should have done something more purposeful with it. At the moment it looks like there was little thought put into that, or that they decided they'd just go for a pretty face shot and ignore any notion of concept. Could probably have gotten away with it had she had a softer, pastel hair colour. Better composition/styling/art direction.
nice one!