I'm not entirely against the idea, but without the icon the desktop notification looks more like the "original" notification. That's why I implemented it the current way.

Can you please add some screenshots so that others can evaluate the idea?

He said "if the large icon is not available". I guess we can assume that if an icon is provide then it's better than none?

Cannot really comment on the patch but it certainly seems harder to get a big icon than a small one!!

Could you provide a screenshot before/after for VDG imput?

I like it, specially because we are talking about Android notifications, but also Plasma make a lot of use from Icons in notifications and I prefer to have them because they make it clear what kind of notification it is and I know if I have to care about before I need to read it completely.

No general objection from my side, the only concern I have is that the small icon might be very low-res and look uglish when scaled. But this is just gut-feeling. Have you tested on real examples?

In D10165#208131, @nicolasfella wrote:

No general objection from my side, the only concern I have is that the small icon might be very low-res and look uglish when scaled. But this is just gut-feeling. Have you tested on real examples?

I haven't, I'll look into that.

Is there any guideline for the plasma icons recommended size? I'd imagine that some people with HiDPI screen might want even larger icons send over than 128x128.

Here's an example with a 24x24 pixel icon (way smaller than happens in practice):

I think that's good enough, especially considering that this is the worst case.