layer at (0,0) size 800x600
  LayoutView at (0,0) size 800x600
layer at (0,0) size 800x216
  LayoutBlockFlow {HTML} at (0,0) size 800x216
    LayoutBlockFlow {BODY} at (8,16) size 784x192
      LayoutBlockFlow {P} at (0,0) size 784x20
        LayoutText {#text} at (0,0) size 378x19
          text run at (0,0) width 378: "The square below should be exactly 50 pixels high on the ruler."
      LayoutBlockFlow {DIV} at (0,36) size 784x156
        LayoutImage {IMG} at (45,0) size 50x50