1. A computer-implemented method for generating an image of a toy construction model constructed from toy construction elements of a toy construction system, the toy construction elements comprising coupling means for releasably interconnecting the toy construction elements, the toy construction system comprising one or more marker construction elements comprising such coupling means and each having a visual appearance recognisable by an image processing system; the method comprising: capturing, by a digital camera, an image of a toy construction model constructed from the toy construction elements; processing, by a digital processor, the captured image to detect a position of at least one of the marker construction elements within the captured image; responsive to the detected position of the marker construction element, generating a computer-generated image; augmenting or replacing the captured image with the generated computer-generated image; and displaying, by a display, the generated computer-generated image or the captured image augmented with the generated computer-generated image.