Currently, a spammer seems to be expending a great deal of energy to send out embedded images that just consist of a white background with a few randomly-colored and -positioned diagonal lines. It's possible that this is some subtle ploy to disable image-savvy filters but it's more likely to be just another spammer screw-up. The spams are probably meant to be stock spams, as they resemble some recent spams promoting WBRS.PK. He must be wondering why whatever he's advertising isn't taking off ...