The interior design of the Rex included a variety of ornate features; the designer is not known but it is assumed to be the work of Mollo and Egan who collaborated with Nye on other cinema interiors. The Rex interior featured stylised floral stucco friezes around the dining room, a striking decorated foyer ceiling rose, and the nautical flavour set by Nye's dining room porthole windows was continued with the addition of scallop shell-shaped light fittings and stucco waves in the auditorium. The main screen itself was surrounded by an ornate proscenium, with Art Deco floral designs obscuring the ventilation grilles.