I m all for pictures of models in the narrow sense i.e. of miniature copies of real machines but my definition of model is much wider. Engineering models rather than model railways, toy soldiers, and baby traction engines, lovely though they all are.
To me a model is
anything that represents the structure and/or behaviour of the real world. Models can be diagrams, words, numbers, formulae, symbols, graphs, 2D plans, and computer programs just as effectively as a physical build. Modelling includes ideas and concepts, verbal descriptions of mechanisms, chemical formula, and music. Einstein s Theory of Relativity is a Model, and so is Ohms Law.