DMT hallucinations are very different, and a lot more vivid, than those from LSD or mushrooms. With the latter, at least with eyes open and in reasonable doses, the effect is not so much as seeing "new things", but seeing the same thing somehow differently. There may be some slight morphing-type movement, but it's still obvious that you see the "same things". I don't think the visual effects are really significant part of LSD/Mushroom trips. They are just easiest to verbalize (unlike e.g. some weird brainfucks like forgetting what a door does), so they are talked about more.

With DMT it can be as if someone suddenly put VR glasses on you.