Hilary Duff<\/strong><\/a>\u2019s latest Instagram post is what dreams are made of.<\/p>\n Duff, 38, sent fans into a frenzy on Tuesday, October 7, when she shared photos<\/a> and a video of herself in what looked to be some sort of rehearsal studio. In one snap, she took a mirror selfie as she knelt on the ground in shorts and a tank top, flashing a huge smile. A mic stand could be seen in the background. The second photo showed Duff in a different outfit \u2014 this time wearing animal print pants and a crop top \u2014 as she covered her face with her hands and stood in front of the mic.<\/p>\n The slide that really got her followers reeling, however, was the brief video clip that showed Duff laughing and pushing the mic stand away from her body. Her 2003 hit \u201cWhat Dreams Are Made Of,\u201d which her titular character sang in The Lizzie McGuire Movie, could be heard playing in the background.<\/p>\n Some fans believed that the snippet played in the video sounded slightly different than the one Duff performed in the Disney Channel movie, meaning that the singer may have re-recorded the track.<\/p>\n Exes Joe Jonas and Demi Lovato Reunite at Jonas Brothers Concert, Perform \u2018Camp Rock\u2019 Duets<\/a><\/p>\n \u201cTHE RE RECORDING OF WHAT DREAMS ARE MADE OF\ud83d\ude2d\ud83d\ude2d\ud83d\ude2d,\u201d one user commented on the post.<\/p>\n Another fan responded, \u201cThat is what I was wondering too! It almost sounded like updated vocals.\u201d<\/p>\n \u201cIt is!!! 100 percent,\u201d a third person wrote.<\/p>\n Other fans shared their theories regarding what Duff might be rehearsing for, with some suggesting a possible upcoming tour.<\/p>\n \u201cA concert?? A tour?? A live performance?? Whatever it is I\u2019m there \u2764\ufe0f,\u201d one fan commented, while another person added, \u201cTOUR REHEARSAL? Sister sign me up I\u2019m traveling this year!!!!!!!!\u201d<\/p>\n Hilary Duff\/Instagram<\/span><\/p>\n One fan shared Duff\u2019s post via a now-viral TikTok<\/a> along with the theory that she might be scheduled to perform as a surprise guest for the Jonas Brothers during their Greetings From Your Hometown tour stop in Houston on October 19. (Houston is Duff\u2019s hometown, and many of the band\u2019s previous special guests<\/a> have been performing in their hometowns, as well.)<\/p>\n A few users pointed out that Joe Jonas<\/strong> liked Duff\u2019s post. Others noticed that a man could be heard laughing in the background of Duff\u2019s video and claimed it sounded like Kevin Jonas<\/strong>.<\/p>\n A guest appearance from Duff would certainly be timely given her recent announcement that she would be returning to music<\/a> after a 10-year break. In addition to signing a deal with Atlantic Records, Duff has a docuseries in the works that will document her \u201clong-awaited musical return and personal journey, offering an unfiltered vignette into Hilary\u2019s world,\u201d a September 9 press release revealed.<\/p>\n<\/span><\/div>\n