YI M1 has a
20.0MP Four Thirds (17.3 x 13 mm ) sized CMOS sensor . On the other hand, Leica TL2 has a
24.0MP APS-C (23.6 x 15.7 mm ) sized CMOS sensor .
Below you can see the M1 and sensor size comparison.
As seen above, Leica TL2 has a 1.6x Larger sensor area than YI M1. 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.