In a telephone conversation with Business Insider on Thursday evening, McNeill explained that the dress in the picture was worn to her friends' wedding. Some people see the dress as it appears in the photo as white and gold, while others see it as blue and black.
The dress was worn by the bride's mother. McNeill and her friends first realized something was different about the dress when the mother sent her daughter the now-famous photo.
"What happened was two of my close friends were actually getting married and the mother of the bride took a photo of the dress to send to her daughter," McNeill said. "When my friend showed the dress to her fiancé, they disagreed on the color."
The bride then posted the picture on Facebook, and her friends continued to debate the color of the dress.
"All of our friends disagreed," McNeill said.
After seeing the Facebook thread, McNeill decided to share the picture on a fan page she has on Tumblr dedicated to a woman named Sarah Weichel. That was where the dress went viral.
Weichel is a talent manager who represents several YouTubers including Hannah Hart.
Weichel told Business Insider her phone began blowing up on Thursday after McNeill's post started going viral.
"The crazy thing is, I actually have nothing to do with the post," Weichel said. "It's literally just a fan account of me, so my name and my photos are all over the account. I actually don't have anything to do with it ... But I have been getting a ton of phone calls and emails tonight."
The situation was even weirder for Weichel because also on Thursday her client, Hart, was just announced as the star of a new television series.
"Between that announcement and the dress thing my phone has been going crazy with congratulations and, 'What the hell is happening?'" Weichel said.
For Weichel, there is no question about what color the dress is.
"Black and blue of course!" she said.
Weichel put Business Insider in touch with McNeill, who said one of the oddest parts of the experience had been watching celebrities share her picture.
"I thought my followers on Tumblr would maybe have a good reaction, but I never would have considered that Taylor Swift and Mindy Kaling would be tweeting about it," McNeill said.
Of all the celebrities who became interested in her post, McNeill would like to meet Swift.
"Oh my god," she said when we asked about Swift. "That would be something."
McNeill plays guitar and sings in a band named Canach that plays what she described as "traditional Scottish folky music." Her band played at the wedding. She actually saw the dress in person and told us definitively what color it really was.
"I got to the wedding and the mother was wearing the dress," McNeill said. "Obviously it was blue and black."
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