Size and weight is a big decision factor when you are trying to find the ideal camera for your needs.
In this section, We are going to illustrate Nikon S6100 and Canon M side-by-side from the front, back and top in their relative dimensions. Nikon S6100 has external dimensions of 98 x 58 x 27 mm (3.86 x 2.28 x 1.06″) and weighs 175 g (0.39 lb / 6.17 oz) (including batteries). Canon M has external dimensions of 109 x 66 x 32 mm (4.29 x 2.6 x 1.26″) and weighs 298 g (0.66 lb / 10.51 oz) (including batteries).
Below you can see the front view size comparison of Nikon S6100 and Canon M. Nikon S6100 is clearly the smaller of the two cameras. Its body is 11mm narrower, 8mm shorter and 5mm thinner than Canon M. As you can tell, actually this is not a fair size comparison since Nikon S6100 has a built-in lens but Canon M doesn't. Once you put a lens on M, its thickness will increase significantly.
Comparison image of Nikon S6100 and Canon M Size, Weight and External Dimensions - Front View
Here is the back view size comparison of Nikon S6100 and Canon M.
Comparison image of Nikon S6100 and Canon M Size and Weight - Back View
Now lets look at the top view comparison of Nikon S6100 and Canon M.
Top View Comparison image of Nikon S6100 and Canon M Size
Weight is another important factor especially when deciding on a camera that you want to carry with you all day.
Nikon S6100 is significantly lighter (123g ) than the Canon M which may become a big advantage especially on long walking trips.
Again, this comparison may not be very useful in real life as we are comparing the weight of a camera with a built-in lens to the body-only weight of an interchangeable lens camera. Once you put a lens on M, the total kit will weigh much higher.
Weather Sealing
Unfortunately neither Nikon Coolpix S6100 nor Canon EOS M provides any type of weather sealing in their body, so you have to give extra care especially when you are shooting outdoors. If weather sealing is a must-have feature for you, check these sections: Top Compact Cameras with Weather Sealing Top Mirrorless Cameras with Weather Sealing
LCD Screen Size and Features
Nikon S6100 and Canon M's LCD screens has the same diagonal size of 3".
Unfortunately, both cameras has fixed screens so they don't tilt or flip in directions.