Canon M6 MII has a 33.0MP APS-C (22.3 x 14.9 mm ) sized CMOS sensor and features DIGIC 8 processor. On the other hand, Sigma fp has a 25.0MP Full frame (35.9 x 23.9 mm ) sized BSI-CMOS sensor .
Canon M6 MII's sensor provides 8MP more than Sigma fp'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 M6 II and fp sensor size comparison.
![Canon M6 MII vs Sigma fp Sensor Size Comparison]()
Sensor Size and Resolution Comparison image of Canon M6 MII and Sigma fp Cameras
As seen above, Sigma fp has a 2.6x Larger sensor area than Canon M6 MII. Larger sensors give photographer more control on the depth of field and blurry background compared to smaller sensor when shot in same focal length and aperture.