Panasonic ZS70 has a 20.0MP 1/2.3 (6.17 x 4.55 mm ) sized BSI-CMOS sensor and features Venus Engine processor. On the other hand, Canon M3 has a 24.0MP APS-C (22.3 x 14.9 mm ) sized CMOS sensor and features DIGIC 6 processor.
Below you can see the ZS70 and M3 sensor size comparison.
As seen above, Canon M3 has a 11.8x Larger sensor area than Panasonic ZS70. 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.