pkg upgrade?

[Walter Hurry]

Copied from terminal and pasted here:
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$ sudo pkg upgrade
Updating repository catalogue
Repository catalogue is up-to-date, no need to fetch fresh copy
The following packages will be upgraded:

	Upgrading gcc: 4.6.4.20121102 -> 4.6.4.20121123

The installation will free 1 GB

88 MB to be downloaded

Proceed with upgrading packages [y/N]: y
gcc-4.6.4.20121123.txz              100%   88MB   6.8MB/s   6.0MB/s   
00:13    
Checking integrity... done
Upgrading gcc from 4.6.4.20121102 to 4.6.4.20121123... done
$
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OK, fine. But what's this about 1GB being freed?