The ‘Compressed: Yes’ tells you whether the file was transferred as a compressed file over the Internet. The ‘Content-Length’ is the byte length of the file. Comparing this to the Encoded/Decoded/Transferred size will tell you how much your file has been compressed.
If your file is not compressed and you are running a Apache server, add this .htaccess file to the root of your folder. More server configurations to enable GZIP can be found in the HTML5 Boilerplate server config area: https://github.com/h5bp/server-configs