The three references %object% %object1% and %objects% are in fact the same reference, so if you use one of them and then print out the contents of all three, you will find that they all have the same value.
But the GUI treats them as different references, and will list them in restrictions and actions seperately as:
[Referenced Object]
[Referenced Object 1]
[Referenced Objects]
This could be confusing to new users.
It would be better if they were in fact three different references.
Or if they are the same reference then drop-down lists in restrictions and actions should use the same name for all three:
[Referenced Object(s)]
%object% and %object1% are synonymous, the latter being useful when you have more than one object reference. However, %objects% is a distinct (and special) reference that matches on multiple reference, whereas the other references will only match a single item.