It's slang for a bad knockoff, a tawdry copy of something. Temu is a Chinese retail site selling knockoffs of other companies' products, but they have the knockoffs made in sweatshops by slaves in Xinjiang for nothing. That way, the site can sell stuff cheaper than anyone else. China also has a very "flexible" view of the intellectual property rights, patents and trademarks of other nations, which saves them money when they rip off products.