“relatively large swath of light-colored smooth terrain appears”
I will bet that’s where the tail comes from - the deposit of ices. This isn’t a “great comet” and there doesn’t seem to be much of those ices left. This should be interesting to watch as the comet comes closer to the sun and warms up.
The amount of small detail on the surface on one of these two hunks of debris joined as if as one is pretty amazing, and I agree, their transit should be very interesting.