GoPro Hero11 Black Mini has a
24.7MP (1/1. ) sized CMOS sensor . On the other hand, GoPro Hero6 Black has a
12.0MP (1/2. ) sized CMOS sensor and features GP1 processor.
GoPro Hero11 Black Mini's sensor provides 12.7MP more than GoPro Hero6 Black's sensor, which gives a significant advantage in real life. You can print your images larger or crop more freely.
On the other hand, please keep in mind that Max sensor resolution is not the only determinant of resolving power. Factors such as the optical elements, low pass filter, pixel size and sensor technology also affects the final resolution of the captured image.
Below you can see the Hero11 Black Mini and Hero6 Black sensor size comparison.
GoPro Hero11 Black Mini and GoPro Hero6 Black have the same sensor sizes so they will provide same level of control over the depth of field when used with same focal length and aperture.