Here's a quick pass to check real type of the file on Unix-like platform:
using the "file" command, like:
file e3f8794a5c226d4.jpg
and output is
e3f8794a5c226d4.jpg: PNG image data, 3768 x 2640, 8-bit/color RGBA, non-interlaced
which will print file information details, and can also check if the specified file has been destructed.