The image syntax is limited, in that it allows for only images to be made into
sidebars. This has led to the use of tables and custom DIVs to create navboxes
such as [[en:Template:OSIModel]].
See [[en:Wikipedia talk:Extended image syntax#Multiple images in one frame]] for
an example of the usefulness of generalized frames and sidebars. Use of HTML
should be deprecated, but right now there's no better way of making these.