FROM THE 9TH JUNE 2015 UPDATES VIA S/K: Super Neighbours: When you click on a neighbour in the main neighbour panel you will see a new 'Set as Super-Neighbour' option. It's main purpose is to allow you to select one (or may be a few) neighbours that will be permanently hired to work your farms when you go on vacation or have to be absent from the game for a while.
All Super Neighbours will have a red dot in the neighbour bar. You can also use the Order by Super-Neighbour option if you want to see all the Super Neighbours grouped together.
Also for the next release, we hope to extend this concept to the cooperative design as well. Meaning, if a Super Neighbour have the design permission on one of your farms, he will be allowed to move, delete coin items and even buy items with their own coins to put in your farm (based on the farm owners level), this way you can have groups of trusted farmers designing different sections of a farm without requiring your online presence on that farm.
FROM THE 30TH JUNE 2015 UPDATES VIA S/K: Super Neighbours can now plant your farms: There is a new check box 'Allow Planting' in the Edit Super-Neighbour window that will grant permission to the Super-Neighbour to plant crops in your farm. He/she will be making the decision of what to plant, the coins will be deducted from the farm owner's account and the farm owner and the Super-Neighbour will earn 2 XP for each field planted.
FROM THE 31ST JULY 2015 UPDATES VIA S/K: Super Neighbours can now design at your farms: There is a new check box 'Permanently Hired for Design' in the Edit Super-Neighbour window that will grant permission to the Super-Neighbour to go anytime to the farm you selected and start designing, you don't have to be online for this to work.
The Super Neighbour will be able to use any Free Style tools that you own or that she/he owns.
In the next few days we will add a checkbox "Allow selling and purchasing items with my coins" so the farm owner can give extra permissions to Super Neighbours to buy new items for the farm or selling any items in the farm to provide more flexibility when designing together.
Other Super Neighbours Improvements:
a) If the owner of the farm owns a Manure Spreader or a Mobile Sprinkler you will be able to use them after you finish planting.
b) When selecting a seed to plant, the Tool tip with the amount stored will reflect the amounts for the farm owner (not yours), same for the belts shown.

I have provided this link to Slash Key (the game developer)
for you the Farmer to gain a better understanding of "Neighbours".