I know the focus is on distinctively visual, so that any texts with especially effective visuals can be used, but the most successful ones are often those that you can link to either the techniques and/or the main ideas in the prescribed text. For this reason, texts which have connections to ideas such as friendship, courage, resilience the brutality of war and/or the dishonesty of those in power are useful since these are focuses in "Shoe-Horn". A few visual texts which have at least 2 of these concepts include "Beneath Hill 60", "Gallipoli", "The Nuremburg Trials" and "Munich." You make make strong associations through the theme(s) with specific textual references as to where these are seen as well as HOW the ideas are revealed through distinctively visual features, such as camera work, lighting and special effects in the film as well as lighting, symbolism, and the photographs in the play. Don't forget that the sounds (music+dialogue) help the audiences to imagine the experiences of the speakers-to VISUALISE what each is saying-so these techniques can be discussed as supporting the more obvious visual techniques that are usually mentioned. All the best.