Upper panel: RGB cutouts (with the same filter combinations as used in Fig. 1) of cluster members 8971 and 5068 with surrounding multiple-image systems K33, K77, and K111. The inset cutout shows the counterimage K33.4. Gold, silver or bronze colours indicate the category (reliability) of multiple images. Dotted and dashed lines with arrows represent the orientation of 150C and 150R grism spectrum, respectively. They are also indicated on the bottom two panels. The dotted line indicating the 150C spectrum orientation extends to galaxy 8971, positioned 6″ to the northeast of galaxy 5068. Second panel: RGB cutouts with removed cluster galaxies, enabling a better colour comparison. Third panel: F200W 150C grism spectrum of galaxy 5068 showing potential [O III] emission lines observed at 2.1 μm from K33.6 and K33.7, and emission from K33.2, K77.1, and K33.5 on the left. The wavelength calibration matches the spectrum of galaxy 5068. Fourth panel: F200W 150R grism spectrum of galaxy 5068, indicating the [O III] emission of K33.6 and K33.7.