So uh... unless Tails fucks with the kernel, Linux isn't gonna give a fuck what the file extension is. It doesn't even look at it. Whatever funky launcher Tails uses might, but if it does, it breaks with Linux tradition.File's fine as far as I can tell man. Pretty nice looking picture too. I actually know exactly who sent you this now, since I recognize the work (but of course I can't say) :P