To check the embedded files within a binary file.
$ binwalk nineveh.png
DECIMAL HEXADECIMAL DESCRIPTION
--------------------------------------------------------------------------------
0 0x0 PNG image, 1497 x 746, 8-bit/color RGB, non-interlaced
84 0x54 Zlib compressed data, best compression
2881744 0x2BF8D0 POSIX tar archive (GNU)
even though, the binary is image, we see that a tar file has been embedded in it. to extract it.
$ binwalk -e nineveh.png
DECIMAL HEXADECIMAL DESCRIPTION
--------------------------------------------------------------------------------
84 0x54 Zlib compressed data, best compression
2881744 0x2BF8D0 POSIX tar archive (GNU)