Sony has revealed that the long-awaited compact variant of its 2019 flagship is called the Xperia 5. It shares an OLED "TV-grade" screen with the 1; however, this panel measures 0.4 inches less than its regular-sized counterpart. The 5 also has the same triple cameras and Snapdragon 855 SoC as the 1.
https://www.notebookcheck.net/Sony-unveils-the-Xperia-5-a-new-compact-version-of-its-flagship-phone.434438.0.html
158mm isn't very compact. It was kind of the "standard" length 2 years ago. They should return to the days of sub 130mm compact. The last compact was 135mm. Before that was 129mm.