Zhang Weiyi, 21, another fan, says the aesthetics of those buildings are still striking. "Postmodern high-rises and residential blocks with decorative window grilles featured playful colors and shapes — like children's drawings. Compared to today's 'glass bead' office towers, they have depth and warmth," she says. "They witnessed a generation's childhood and naturally trigger memories."

Liu tags many of his photos with three keywords: architecture, urban memories, and dream core, a popular concept among post-2000s. It refers to a surreal, nostalgic online visual style designed to evoke dreamlike feelings.

Chinese-style dream core often features blue glass windows, aluminum frames, tiled walls, green electric fans and enamel cups, objects once common in everyday life.

As Liu says, the post-2000s generation is the first in history to document and revisit its own childhood digitally, making them particularly sensitive to old photos and nostalgic memories shared online.

Du says Chinese-style dream core also reflects a stage of the country's development. "Every generation has collective memories tied to childhood objects," he says, adding that they should be properly preserved to create new business opportunities.