The 19-year-old rapper sports a blonde quiff and Mr Men boxers in an image that was used to promote her DJ work.
Rundle revealed on Twitter, after the photos were published in the press, that they were taken in early 2012.
Speaking to Digital Spy last week after teaching us to play the drums, MK1 revealed that they are trying to give mentor Louis Walsh an education in rap.
"Louis Walsh understands what we're trying to do. And for him we're a breath of fresh air," MK1 member Simeon Dixon said. "By the end of the series he'll be ready to rap."
The X Factor continues Saturday (October 20) at 8.20pm on ITV1.
Digital Spy breakfast show - watch Anna Williamson discuss the day's biggest stories including Girls Aloud, X Factor and The Great British Bake Off: