By material design guidelines, this is what a notification looks like on Android M and Android N:
Now, what are the image assets needed for the developer to implement it this way? I haven't found any specific size requirements either, but based on screenshots, the large icon/avatar is 40px in 1.0x mdpi resolution.
Let's say this is the layout of the notification for Android M:
What I thought was needed was the icon as seen in (1) which then gets masked to a circle by code and then the small icon is added using a different image. But I have been told that it's not possible and an image similar to (3) is needed. But that doesn't sound right since it wouldn't be aligned properly with the notifications that don't include the small app icon and since it looks different in Android N, it wouldn't work either.
So the question is, which images (and what size are these) does a developer need to make it look like the image from the design guidelines? I assume that a different image (the small icon) for M and N is needed as well?
Thank you.
/e just to clarify, I am asking as a designer, not a developer, otherwise I would try it myself
