After blowing her fans' minds with her epic Eras Tour for nearly two years, Taylor Swift is peeling back the curtain to show how the complexity of the production blew everyone's mind as it was happening, too. Swift's mom Andrea sits in awe during one sequence from the first trailer for 'The End of an Era' as her daughter rattles off from memory a sequence of music seemingly from one of the ever-changing acoustic sets. "That's complicated," Andrea declares after Swift ran it down, with the rest of the trailer showing the complexity of the entire ambitious tour, which also happened to coincide with her working on new and re-recorded albums, and her burgeoning romance with Travis Kelce, who features prominently in the star-studded footage alongside the likes of Sabrina Carpenter, Ed Sheeran, Florence Welch, and Gracie Abrams. The 6-part 'End of an Era' launches with two episodes December 12 on Disney+.