I posted this in the photo section - with no reply. Bill suggested duplicating here. I am reasonably interface savvy but can't work out this one..
I tried putting a couple of shots from my most recent trip on:
Favorite Backcountry Photos & Albums
but couldn't quite work out how to do that.

> click "new image"
The two options seem to be
1 - link to a webpage (which I could do if that's the only way)
2 - enter a media tag (prefer not to)

Other posts just require a URL.
On other photo posts I see inputs for thumb, medium, full-size.
What am I missing here?

Thank you.