I have downloaded an image that someone has uploaded to my website with a public upload form.
My intention was to copy the file in a virtual machine and see the image from there; unfortunately, on ubuntu there is something called "thumbnail"...
So, thumbnail was created and I can see the image in the file explorer, but I've never clicked on the file.
I run on standard Ubuntu 14.04 (previously lubuntu-desk was installed in this way sudo apt-get install lubuntu-desktop).