Its source is the optimistic "future" imagined around 1999–2003, when millennium excitement mixed with anxiety — Windows XP's blue sky, early iPod ads, MSN Messenger emoticons all carry that mood. It resurfaced in web design in the 2020s alongside a broader Y2K fashion revival.
Visually: chrome-reflective silver gradient text, puffy bubble-lettered 3D type, iridescent holographic gradients that shift hue with angle, and scattered sparkle/heart stickers. You don't need real 3D rendering — layering several colors with linear-gradient and clipping it to text with background-clip: text fakes the chrome look convincingly.
It's used to evoke nostalgia on Gen-Z-facing fashion, beauty and music-artist pages. It works best scoped to a mood-setting hero section rather than screens where information clarity is the priority.