Mars Attacks: Occupation #5 came out yesterday from IDW. While this morning artist Andy Kuhn posted his thumbnails for the issue on Facebook. He says it takes him roughly two days to thumbnail out a full issue. I've put some preview pages for the issue below so you can see how his thumbnails compare to the finished pages.
In the case of page 1, it went from a large splash of the planet to a two page set up establishing the whole Earth first and then zooming in. While page 2 on the other hand stayed almost exactly how he thumbnailed it.
The series is being written by John Layman and colored by Jason Lewis.