Imagine Dragons
I think they are Performers because they haven't got a alternate image and come across as themselves as normal people.
A star is relative to who you like and what you like. This means an individual will see someone as a star when someone else will not or as much of a star due to their personal tastes. In perspective of Imagine Dragons they are not quite as well known, as their marketing is not as pushed like other stars like Miley Cyrus.
There is a normative image about them making it hard to tell if they have created a persona. Although there outfits match genre conventions (dark with denim) but still look casual.
Miley Cyrus

Star - Created a persona. She acts her age by being youthful at 21 just coming of age to drink. She is quite rebellious in her actions both in her music videos and in public appearances, almost always trying to stand out in whatever she's doing.
She has a disregard for social values as she dresses inappropriately for example in the music video "Wrecking Ball" she is wearing almost nothing during the video. She has also succeeded against all odds because she is hated among many individuals.
Richard Dyer's paradox 1 states that "The star must be simultaneously ordinary and extraordinary for the consumer."
In relation the Imagine Dragons they come across as casual, normal ordinary people but are extraordinary because of their talent, record label and stage presence.