GDPR is more for storage of data.
CCTV cameras are similar, they should only capture your own property and if you are capturing the public road for instance you should only keep the data for an acceptable period normally a few weeks.
Slightly different with a drone as we have the 50m rule which is purely privacy related. You shouldnt really be flying within 50m of your neighbours property without permission. I’m guessing it’s this that the permission is for.