Besides being the role of female actress Juliette Lewis in the Oliver Stone film "Natural Born Killers" there is more than one artist with this name (see links in the Wiki sources):
These are photos from concerts where Mallory Knox played, so they may be of other bands that played the concert as well.
Vans Warped Tour Nov 29, 2013 Brisbane, Queensland, Australia Uploaded by Wattoson
Hit The Deck Festival 2013 Apr 21, 2013 Nottingham, England, United Kingdom Uploaded by Gwyn Williams