Viewport <#document> at (0,0) content-size 800x600 children: not-inline
  BlockContainer <html> at (0,0) content-size 800x416 [BFC] children: not-inline
    BlockContainer <body> at (8,8) content-size 784x400 children: inline
      TextNode <#text>
      InlineNode <picture>
        frag 0 from ImageBox start: 0, length: 0, rect: [8,8 400x400] baseline: 400
        TextNode <#text>
        InlineNode <source>
        TextNode <#text>
        ImageBox <img> at (8,8) content-size 400x400 children: not-inline
        TextNode <#text>
      TextNode <#text>

ViewportPaintable (Viewport<#document>) [0,0 800x600]
  PaintableWithLines (BlockContainer<HTML>) [0,0 800x416]
    PaintableWithLines (BlockContainer<BODY>) [8,8 784x400]
      PaintableWithLines (InlineNode<PICTURE>)
        PaintableWithLines (InlineNode<SOURCE>)
        ImagePaintable (ImageBox<IMG>) [8,8 400x400]
