The correct overlay (xmp-points scaled [0;1]x[0;1]=>[0;3600]x[0;2974])
My impression is, that the confusingly stroked area (with the SETI signal) is irrelevant, it's also used for the password already. Attention should be payed for the channel number and the 51 bytes headlines and somehow the marked line on the right.
Huh! That's pretty interesting. I must admit I thought you were on a wild goose chase when you started out down that path, but it certainly does look like something deliberately hidden.
For the record, to whoever asked a few pages ago, the image I posted that I'd "found" with the Such Wow Doge meme was what I thought was an obvious joke.