Xiaomi used to make special variants of its flagships that had semi-transparent rear panels. They called them Explorer Editions and made one for the Xiaomi Mi 8 and Mi 9. But they said they wouldn't release a Mi 10/10 Pro Explorer Edition, despite leaked images of just such a prototype in the wild. It turns out they made a prototype of a Redmi K30 Pro Explorer Edition as well, as per images from Xiaomi Senior Product Manager Daniel D on Twitter. He calls it a custom Redmi K30 Pro, which likely means that it isn't going on general sale anytime soon (or alternatively Xiaomi is checking to...
Source: https://www.gsmarena.com/xiaomi_made_a_redmi_k30_pro_explorer_edition_but_it_may_never_go_on_sale-news-43223.php