Mariah Carey proved that she's never looked better when she stopped by The Ellen DeGeneres Show on Monday. While the audience was attempting to lip-sync Mariah's hit song "Emotions," she walked out unannounced in a gorgeous red and pink dress. The audience rightfully gasped and cheered at seeing Mariah before she revealed an exclusive sneak peek of her music video for "Infinity." Watch the cute clip above to see Mariah's sweet surprise, then check out her epic performance of an old classic at the Billboard Music Awards on Sunday.