(From https://bugzilla.gnome.org/show_bug.cgi?id=601825) To reproduce, open a message in gmail with a .jpg file attached and click the "view" link next to the image. The image opens in another window. Wait until it is displayed. Then right click and choose "save image as". The "download this file?" dialog pops up but it can't recognize the file type and when you choose "save as" and save it, the file turns out to be a little HTML file containing something like this: <html><title>foo.jpg - iola Mail</title><body><img src=/a/iola.dk/?attid=0.1&disp=emb&view=att&th=124e8ecad0854ea6></body></html> This is an old bug, actually before epiphany-webkit I think it worked properly sometimes, but now it always fails on me. I am on Epiphany 2.28.0 on Ubuntu Karmic. Since the "download" link doesn't work either, see bug 598605, I can't get the image file (ah, wait, there's the "download all files as zip"). :) Right-click, "copy image" then inserting it in the GIMP works fine, by the way. And it works in Firefox - not to point fingers, just so you know it's not a bug in gmail.
I bet this is related to the fact that there's a mark saying that the user may not select the image.
Seems to be working now.