The Dream encompasses everything that is, was and ever shall be and for that reason it is a lot easier to glimpse than the Void. Unless you're really unfortunate everything you can see right now is part of the Dream and none of it has anything to do with the Void.
Of course, you could be looking out at the back garden where the little graveyard containing one rabbit four guinea pigs and Socks the cat have all been laid to rest (in a place where such a thing is legal). There's the thin end of that wedge. Life, Freedom, Creation these are all parts of the dream, but so are Death, Constriction, Destruction, not to mention Order and Chaos.
Every despot, dictator, fascist, nihilist and otherwise thoroughly unpleasant megalomaniacal sociopath is part of the Dream, just as everybody else is. Filth is of the dream as much as sunlight, and blue skies. Monday morning happens in tthe dream as often as Friday afternoon.
The Dream is all.
Sorcery is the direct manipulation of the dream by itself using the vehicle of a sentient distinct intelligence. The Dream does not allow just anybody to mess with its stuff. Sorcerer's are built with, or attain through long practice, the necessary understanding to work their magic.
Natural sorcerers start with "talents", a Dream-gifted, innate understanding of one tiny part of the Dream that allows them to, for example, turn all material objects into grey sand. From there a sorcerer works out how to turn grey sand back into objects, or to turn nothing into an apple or some other worthwhile task.
Pure Dream Manipulation
It would, of course, be stretching the point to talk of the Dream being "visible", things are visible and they are part of the dream but all invisible things are too. It would also be stretching the point to talk about the Void "seeing" things. The Void has no single definitive point or set of points where the act of seeing could occur.
To say that all the Void can sense is the Dream, however, is too vague. If you accept the caveat and shorthand: All the Void can see is the Dream then that helps.
What it means is that instead of understanding a teapot the Void only understands that there's a piece of static Dream. A specific agent of the Void may understand it to be a teapot but the general Void does not.
The one thing the Void can definitely see is turbulence in the Dream. Static dream material, or Dream material carrying out an organised process seems to blur together to the void, it's not vulnerable to infection. Whenever the Dream is directly manipulated it causes a weak point in the Dream's surface and this could allow Void taint to seep into the Dream. For this reason directly manipulating the dream is likely to bring a horde of Void agents down upon the manipulator. Directly manipulating the Dream is an act of extremity.
Agents of the Dream
You could say that we are all agents of the Dream. Merely by existing through time we all enlarge and enrich it with something. That's too broad a brush to use for every day purposes, it puts a genocidal butcher in the same box as an ecologically aware medical professional.
Even the latter cannot be said to be an agent of the Dream. No doubt if our environmentally friendly doctor could stop the cutting down of a forest and the building of a factory in its place then they would. But the factory has no more nor less right to exist in the Dream than the forest. The doctor is pro-tree and anti-factory. They have an identity within the Dream that the Dream is entirely ambivalent about.
Having said that, there are actual agents of the Dream just as there are agents of the Void. Agents of the Dream are the Dream made flesh. They have their own agenda and that agenda is, very definitely, the promotion of the Dream. Often, when a sorcerer becomes powerful these agents will attempt to get the sorcerer to surrender their identity back into the raw stuff of the Dream. The conceptual remains of a sorcerer can be used to seed enormous, complex blooms of reality in the Dream.
The agents of the Dream often see sorcerers who choose to retain their individuality as selfish. The agents of the Dream do not care about the agenda of the individual sorcerer, they just care about the promotion of the Dream and the eradication of the Void. For this reason agents of the Dream are no more to be seen as allies than agents of the Void.