I Steven!
That's KM's "drag'n drop" feature. Here's how it works:
Take your browser to an image page. Make your browser ½ size. Open a file manager to an empty temp folder. Hold down on the image and drag it over to the folder in the file manager---and the image automatically downloads to that spot.
Pretty neat, huh?
This is something that the boys over at Mozilla.org have been trying to get to work in Firebird and Mozilla for quite some time---and yet K-Meleon already does an admirable job of it I must say!
You get the error message because you're trying to drop it
within the browser window and it has to be dropped either in a folder in a file manager, or---and I may be mistaken on this---another programme (like an image editor, but I haven't tried it yet).
Hope that helped explain that feature!
Eyes-Only
"L'Peau-Rouge"