The
file-info just reports the contents of the C stat() or fstat() function argument structure, without any processing.
There are subtle differences how structure fields are used on different platforms but this manual page for Linux perhaps gives you an Idea:
http://man7.org/linux/man-pages/man2/stat.2.html . To figure out the size of a directory, you would have to write a function yourself, using
file-info on all files in a directory.