New Channel Icon Structure?

I've been searching any docs I can find for the past few hours to no avail, so I figured I'd just ask here.

 

I adapted the Food Network and HGTV channels into two new channels for two channels with similar website structure, and now just need to change the icons.  However, I can't figure out how their channel icons work as there are no icon-default or art-default files as I would expect.  Looking into it, most of my updated major channels (ex. ABC, NBC, HGTV, Food Network) no longer have icon-default and art-default.  Did the standard practice for channel icons change?  How do channel icons work now?  Where do I need to put the icons for channels now?

No, this did not change, you can still put your icons and background art in the Resources folder inside your channel bundle and refer to them using R() (short for Resource.ExternalPath).

The only thing that's changed is that for some of the channels we host the icons and art on a CDN. PMS checks for this by looking at the channel identifier. But this is not standard or required.

Got it.  That makes a lot more sense.