ポスト=mailbox.
This seems to be one of those more cruel 2ch ASCII pictures, because there was some hospital in one of the prefectures that put in a 'baby drop-off' (referred to as a ポスト as well) for parents of unwanted babies to 'drop off' their babies so that the hospital could take care of them and find people who would adopt the babies. (Germany also has baby drop-offs in many hospitals.) It's been getting a lot of controversy lately, and I think that the picture is probably depicting Nono and her husband abandoning the baby at that 'baby drop-off'. Needless to say, doinkies really doesn't think that Tsuji or Takayasu would want to do that, not to mention they said that they would keep and raise the baby at the press conference they had. I suppose it's typical of the really doinky 2channelers to post something like that though.