I believe he's referring to the bottom pic that shows the underside of cylinder 5. It does look kinda weird? Not to freak you out or anything but stranger crap has happened out there!! There's too many stories about "new" block problems. It does look like a crack from the cylinder liner down. What interesting is that the
oil ran down and followed this "line". Could be a casting mark, could be nothing, or could be a crack. Sometimes pictures will ring out the negative sides of things with flashes in all. I would spray down with brake clean and probe that sucker. Maybe a few of our engine experts here will chime in. Other wise looks great! Hang in there!! Regards, Matt