I have added images to some chapters of Signy Kráka. More may follow.
The chapter, "Arrival", even has a video of a reconstructed model of Birka town, if anyone would like to see that.
Birka is believed to be bigger than shown on this video though, and also believed to have had more long jetties into the water. Compare with the image in that chapter to see the difference.
In my description of Birka in this story, I have tried to be as up-to-date on archaeological findings as I could.
Nevertheless, the video does present a good idea of Birka.