Derry, 26, who was performing an acoustic version of Radiohead’s Creep, was told by judges the song didn’t suit her.
But Minogue drew attention to her outfit, comprising a corset-like period outfit with tassles and gown.
“I listened to every word you said, (how) you were oversexualised, you just wanted to sing the song and just wanted everybody to listen to your voice. In the close-ups of this outfit, if you don’t want to be oversexualised (you’re sending) mixed messages. I don’t know if you’re working together as a team.”
“Look what you’re wearing!” RedFoo responded.
“You want to talk about ‘oversexualised’ look what you’re wearing! Let’s get real. Let’s get really real. This is see through!” he directed at Minogue.
Minogue insisted Derry’s idea of her image contradicted her appearance presented by her mentor, RedFoo.
It was an awkward debate for the family-audience show, given it also had little to do with her vocal performance.
Yet later in the episode judges commended 18 year old singer Caitlin Shadbolt on her gold jeans outfit.
“Nobody should ever wear gold jeans again, that is amazing!” said Minogue.
That prompted a close up of her midriff by the show’s director.