The 2020 hopeful sent a video message because he couldn't make it to a labour forum held by the AFL-CIO's Iowa Federation of Labor. However, when it played on TV, the audio sounded abnormally high-pitched, making the audience who watched the message laugh. Washington Post reporter Matt Viser even suggested on Twitter that the mayor "sounded like he’d gulped a canister of helium."
Whoever was operating the video equipment tried to fix the audio as viewers could see a mouse pointer moving across the screen and a box popping up over de Blasio's face, yet the reason for the malfunction remains unknown.
Campaign spokesman Olivia Lapeyrolerie blamed a "technical glitch" when reached by Fox News, writing in an email: "It was obviously a technical glitch. I cannot believe you a [sic] writing a story on this."
De Blasio also said on Twitter that he would make a "less entertaining" video available.