The viewscreen was a viewscreen, allways.
Now, I have no clue what nutbrain in J.J.s team decided to change the screen into a window. Really, what are they supposed to see through that window? Considering the distances and speeds in space they would have to use a zoom. But, who knows, perhaps its a window with a magnifying effect.
Its so silly. On the other hand, now we have a window on the bridge we could invent a new class of villains: