im a kelly clarkson fan but i can say she isnt iconic or not iconic YET depends on how this era will go:
reasons:
if she just continued the success of breakaway era by producing a breakaway part 2 immediately after that phenomenal album she would have been iconic as a pop-rock artist.
however pop-rock isnt that hot anymore its not timely. and being in that genre is a risk because you are too serious for pop and light for rock so she's really in between.
if she continued breakaway with all i ever wanted and now stronger i can her being iconic.
she has all the makings but she refused to be iconic thru following her own creative desires and putting aside fame and commerciability.
however with stronger if wdky will be a HUGE phenomenal hit and followed by Dark Side and would be another monstrous hit and she'll pull off an Adele way and sustain it thru another album I can see she can be.
A person who doesn't want to be a star clearly can't be iconic, but that doesn't mean said person can't be famous/a star.
