It runs Root Nautilus from Home Directory. This can potentially cause root file ownership to be transferred from root to home, even resulting in being unable to boot your system.
It is less secure as it is less precise. It grants root privileges to all GUI during that instance.
Alternatively, you can use pkexec. I wrote a guide on here about how to "mimic' the old "gksudo" days by expanding pkexec and allowing it to perform even if you type "gksudo nautilus" in terminal.