What This is, is full-on Being.
No divisions, separations, witnessing, or causing.
Everything everywhere is YOU. Wherever you turn, there YOU are.
A kaleidoscopic window appears before "your eyes," somewhere in the vicinity of "your head."
In this window appear all kinds of images..
Sensations are experienced and some "objects," like "your body," are rather consistent experiences, while some objects may quickly flit into perception and disappear..
What is separate from what? "Your body" is simply a collection of sensations which constantly change..."Your head," where is it? Can it be verified at all, aside from sensations? Are "you" aware of "your head" at all times, or only when there is an ache or an itch, etc.? Heads come and go, but do YOU?
We look for a feeling of oneness with everything we see, to "prove" that there is only One. We want to know that we are Beingness. We want to feel totally connected to whatever is appearing, and if that feeling doesn't arise, we assume that there must be separation. But who said that a "feeling" is proof of anything? Either of oneness or separation? What we call a feeling is just that: another sensation arising in YOU, as YOU. Does it define the totality of what YOU are?
Skip the feelings and go right to the crux: can "you" know anything at all? Anything? The answer is no, and that puts the brakes on all speculation about oneness or separation, and what is left is simply This. "Trying to know Oneness" is another "happening" in YOU.
Oneness is THIS, right here and now, feeling or no feeling, sensation or no sensation, images or no images. Whatever is appearing is YOU, Be-ing. We can call this Oneness, separation, or Joe - words are just YOU, labeling YOU!
This is it. Full stop! There is no escape and no possibility of something separate, anywhere, anyhow.