Yes, that is a real rotary zoom ring on this Leica Edition Ultra phone

TL;DR

• Xiaomi has teased the upcoming launch of the Xiaomi 17 Ultra Leica Edition, featuring a “Master Zoom Ring,” a physical rotary ring surrounding its rear camera module.
• The flagship device features impressive hardware, including a continuous periscope zoom camera that ranges from 75mm to 100mm (~3.1x to ~4.1x).
• Leaked information suggests that the rotary mechanism may adjust optically variable zoom levels and includes aesthetic cues, such as custom watermarks and red Leica engraving.