In the old days there were two conventions for describing XYZ in 3d CAD. Oddly the bounding-box uses the older convention, which is not used elsewhere within SketchUp. SketchUp uses the more obvious convention, that is, as if you were looking at the 3d object in the real world 'through' the screen as if it were a 'window-frame' - X=left-right/red, Y=in-out/green and Z=up-down/blue. The other 3d CAD convention grew from 2d - it assumed you drew 'on the screen' as if looking down in plan - so bounds.width [~screen-width] is equivalent to SketchUp's X-red, and bounds.height [~screen-height] is equivalent to SketchUp's Y-green; the remaining bounds.depth is SketchUp's Z-blue - originally assumed to project in/out of the plane of the screen - to add the 3d element to a 2d plan ! A '2d' face's bounds has no 'depth' - only width and height [and center] etc Make a note of these odd naming conventions and use them accordingly.