Always Watching, Always Planning

Being connected to people who have Narcissism, whether they're in family, school, work, community, or interest groups, means that while you are focused on what you're doing, they are focused on you, and on other people as well. Their focus is on PEOPLE, and they always have some kind of AGENDA that's under the surface. They may be able to do a certain task or job pretty well, but they are never in a "neutral" state of mind; they always have in mind what other people are doing, what they're not doing, or what they might do, and how what other people are doing might AFFECT THEM and their image and agenda.

In other words, when a target is focused on their work, the Narcissist is thinking about the target doing their work. Not in an analytical way, or a supportive way, but in order to find a way to criticize, or to find a flaw or a chink in the target's armor, or to see how they can suppress or sabotage their progress, or to figure out how they can use the target in some way, or manipulate them, or who to keep away from them.

~If you are a member of any kind of group (family, work, school, community, interest) they are likely to try to control who is connected to who, who is friends with who, and how other people in the group are interacting with one another. If they feel that they need to, they will intercept communication between people, twist or lie about what others said or did (many N.s do this so often that it becomes automatic and pathological), and will often manipulate who is invited and who knows about certain events, and who is not.

~How well you do any kind of task is a CONCERN for them, because if you do something very well, you might "outshine" them, and others might NOTICE and respect, recognize, or admire you for it. Which means you might get more attention or praise than the Narcissist, or even just a little positive attention, and they can't have that. So unless you are already an accepted and established "leader" of a group, the Narcissist is likely to try to diminish you and your talent or ability any way they can.
(A common tactic is to treat you like you're NOT capable, knowledgeable, talented or skilled by simply ignoring and dismissing whatever you do and say. It's an attempt to convince others around you, AND YOU, that you don't really know what you're doing, and that you aren't really capable or competent.)

~How attractive you are to other people is usually of great concern to a person with Narcissism. If others find you more attractive than them, then they feel like they're LOSING a competition for other people's attention and praise. "Envy" and "jealousy" are two different things; envy is about wanting what someone else has for one's self, and wanting the other person NOT to have it. So when a Narcissist ENVIES someone for their looks, it's not that they're "jealous" because someone is ACTUALLY giving that person more attention, or playing favorites. It's that they're ANGRY that the person is attractive at all, and that the person MIGHT GET SOME attention, which means the Narcissist won't get ALL OF THE ATTENTION.
It's the difference between being upset that one's partner keeps dancing with someone else at the party (healthy, normal jealousy), and wanting the person they keep dancing with to suddenly develop a severe facial skin rash and lose their hair. The latter is NOT healthy at all, and is indicative of emotional or mental illness.

~Generally, people with Narcissism want to have control over the other people in their life as much as possible so they can "make" things come out the way they want them to, for their OWN benefit. (For example, fixing a contest so their child will win is not about the child, nor is it beneficial for the child.) They want to be SEEN as "special" (MORE special than others), as THE expert, or as an authority figure, or some kind of "bad-ass", so they can be at "the top" of the group and "over" others in some capacity. Being in a "top position" means that their manipulation is easier to carry out, and they have much less chance of getting caught or getting consequences. So, being "OVER" other people is very important to their usual agenda of manipulation and control.
Again, without being "over" others in some capacity, they will have a much harder time getting away with manipulation or control.