Huawei appears to have filed a patent for a dual-screen smartphone. A Twitter user has envisioned what it could look like, with the second screen located right next to the rear camera module. The device in question could be the Huawei P50 Pro+, but there's no way to know for sure.
https://www.notebookcheck.net/Renders-showcase-Huawei-smartphone-with-a-Xiaomi-Mi-11-Ultra-like-dual-screen-configuration.526810.0.html