Sure.
Its vague because it wants you to define what that means in relation to your own maelstrom, your own brainer, and your own style. What this means is that anyone looking at the object can be targeted by any of the brainers moves that require them to be looking at the target. That therefore assumes that the brainer, at the very least on a subconscious level is aware of the opportunity, and can take advantage of it. I'd suspect this is something that the briner becomes aware of, "Grubber is looking," or "Grubber and Harper just walked before it" and therefore can make his move, " I issue a command." Or however the fictions plays it out.
The only brainer I've had in my games was very much a deviant from the normal. She had something of a hive of creatures that she was part of, not able to see out their eyes, so much as they were empathic extension of her. If she was mad, they were dangerous. If she was looking for someone, so were they. She was a very dangerous brainer in that particular world. One of these creatures she could use as a physic weapon, it was much smarter then the others. She decided that this creature was her relay, and when it was staring down her enemies, she would make her go aggro + other moves through it.
Just the same way, the brainers relay could be a creepy doll. Some voodoo shit that could be placed in the private spaces of others, knowing they will look at this when they least expect it, that the brainer could place this as a way of being creepily confrontational. To get inside the targets head, heart, or soul. I would say that others who look at the brainers relay may realize there is something off about it, just as the brainer realizes they can see it. I'd be hesitant to give the brainer clairvoyance through the move, as it doesn't say the brainer can see them, it says the brainer can make moves as if she could.
On a more practical level,
If we're talking about the relay placed somewhere and Someone approached it or passed it, I would zoom into the scene as if it were the brainer standing at the relay instead. Play it out and let the brainer decide what to do. The brainer knows who but maybe not what they'r wearing, who is just out of sight, the brainer probably cannot make out what they're saying or driving in, or holding. What the brainer knows is who and probably where. That provides context for a lot of information anyway, and allows them to reach into the situation in ways they otherwise would not have been able to. Perhaps they lower their guard because they dont see a threat. Perhaps the brainer is placing her presence in an area where she doesn't have access, or perhaps it's just another player carrying around the charm to provide some weird scary link to the brainer, or maybe just to have the brainers powers as backup.
What it is could be a great many things. I think who the brainer is also provides a lot of possibility. And maybe in your game it's a straight up crystal ball, a two way visual type of deal. They pass the crystal and the brainer see's them through it, maybe then too they could, if they looked, see the brainer. I dont know. I'd ask my brainer.