Season 2 of Loki changed the look of the timelines from season 1, where they were made of blue and purple light, to more solid and tangible, rainbow-coloured shapes that would sometimes be sticky and clump together and also at times calcify and die. The important thing was to go "no glow" on the timelines. None of these closeups ended up in the show but they were still helpful in figuring out how it all works.