As you probably saw, she was giving major 2000s vibes on the red carpet, wearing a navy blue mini dress with jeans and sneakers.
Pretty much everyone agreed that it was a "no" (though Katie herself looked great).
But Katie's standing by her outfit. During an appearance on The Drew Barrymore Show on Wednesday, she said, to her, it made sense for the occasion.
"I knew I wanted to dance there 'cause I was going with my nephews," she said. "So, I threw my sneakers on and I thought I looked cool. I felt cool, I felt great, and then I woke up the next morning and I was like, 'Oh my gosh.'"
Katie said even now, she doesn't understand why her outfit became such a big "thing" and that she doesn't really think about what people had to say about it. "I really don't. I like to go and have fun," she concluded.
Period, Katie! You can see her talk about the look and the inspiration behind it in the video below.