I think within the context of this sci-fi movie explanation, what she was explaining by "unity" is that without time, even matter does not exist. Without proof of existence, was it really there at all? Matter is not static. It is moving. We may perceive something as solid matter, the mountain, for example, but we know that over the many millennia, it may be turned to dust. If humans are not there to see it happen, was the mountain even there? Time gives proof to its existence. Time is the witness. What we perceive has nothing to do with it.Hmmmmm time is unity Sounds good but does it really describe what time is, in fact I would think the opposite. That time is NOT unity. With time there are cracks and crevices to how we experience it, like matter that meets us where we are, just particles moving forward whereas without time there is a lack
of forward momentum. So it's not experienced. Ugh. It is confusing. But also fascinated.
I am sure the writers of the movie script dove into someone's theoretical explanation of it and perhaps embellished a bit, but the basic concept makes sense.