The nitrogen ocean appears to bubble up along the edge of the land ice creating a roiling look which pushes outward. The water ices are small like rubble nearest to land and grow into larger blocks further out.
At the edge of the land ice are craters which are being filled with nitrogen liquid from below as there is no sign of the fluid spilling over their edges.
Eventually these craters will be completely covered and swallowed by the nitrogen fluid. The large icebergs appear to have drifted outward into deeper fluid.
The mounds of undulating nitrogen material appears to flow in from the right and 3 large icebergs are colliding with more numerous small (but still very large) icebergs. These more angular ice block mountains are being mashed into a raised land ice beachfront which is being compressed and exhibits ripples and folds that's assuming everything is moving to the left.
The sharp angular ice is slightly lighter in color than the rippled ice indicating they are likely of differing ages.
This beach of land ice is being pushed westward up onto the main land ice which has a very different textural look.
It took me about two years but I finally figured out what these ice ripples actually are, they are a type of lava called Pahoehoe page 83
Zones 5 & 6
More evidence of the same process. Nitrogen fluid has corralled large mountain blocks of ice into a zone which is bending and twisting and folding the land ice.
The nitrogen flow is migrating north and west. The largest icebergs are at the bottom, as we move north the icebergs become medium sized until they actually start to be ground down to smaller boulders at the very top. This demonstrates how bigger bergs interact with land by grinding down from large to medium size chunks, finally to be reduced from mountain sized to large boulders eventually ground into rubble.
There is even a nitrogen lake trapped between the iceberg mountains and the rippled land ice (roughly center left of the image).