Quickies: in the Vorlon gif, yes, the ship is moving from left to right.
And regarding the B5 gif...bear in mind that there are no other objects in the
frame to give it a sense of perspective. Absent that, there is no way to tell
how big it is, which is why there will be stuff there at all times later on.
The actual dimensions we've worked out in terms of length is that B5 is ten
kilometers long. The rest you can work out from there.