I am confused. 

The 1st time I mirrored the site; it was later cancelled. Later, I chose
'continue'. This completed soon enough but I suspected lots of files not
downloaded yet.

The next time, I chose 'update'. This also completed relatively quick. I right
clicked on the folder for 'properties'. The size of the folder is smaller, and
the number of files and number of folders are lesser than before the update. 

Is it possible that not all files are downloaded still? Is this a very real
possibility?