Viewport <#document> at [0,0] [0+0+0 800 0+0+0] [0+0+0 600 0+0+0] [BFC] children: not-inline BlockContainer at [0,0] [0+0+0 800 0+0+0] [0+0+0 0 0+0+0] [BFC] children: not-inline Box at [8,8] positioned flex-container(row) [8+0+0 50 0+0+8] [8+0+0 50 0+0+8] [FFC] children: not-inline ImageBox at [8,8] flex-item [0+0+0 50 0+0+0] [0+0+0 50 0+0+0] children: not-inline ViewportPaintable (Viewport<#document>) [0,0 800x600] PaintableWithLines (BlockContainer) [0,0 800x0] PaintableBox (Box) [8,8 50x50] ImagePaintable (ImageBox) [8,8 50x50] SC for Viewport<#document> [0,0 800x600] [children: 1] (z-index: auto) SC for BlockContainer [0,0 800x0] [children: 0] (z-index: auto)