Ok so this is what Velleius says:
Quote“These discoveries of Epicurus are so acute in themselves and so subtly expressed that not everyone would be capable of appreciating them. Still I may rely on your intelligence, and make my exposition briefer than the subject demands. Epicurus then, as he not merely discerns abstruse and recondite things with his mind's eye, but handles them as tangible realities, teaches that the substance and nature of the gods is such that, in the first place, it is perceived not by the senses but by the mind, and not materially or individually, like the solid objects which Epicurus in virtue of their substantiality entitles steremnia; but by our perceiving images owing to their similarity and succession, because an endless train of precisely similar images arises from the innumerable atoms and streams towards the gods, our mind with the keenest feelings of pleasure fixes its gaze on these images, and so attains an understanding of the nature of a being both blessed and eternal.
So this is indeed something i had missed previously -- i was thinking that it was just a stream of elemental particles that kept the gods alive in their quasi-bodies, but it appears that the word used is images, not particles, and I can't help but think that that makes a difference. What the difference might be, I don't really know, but there has to be some significance to the things streaming toward the gods being "images" (which I take to be particles organized in shape deriving from their source) rather than just random elemental particles.