Top. Zoomed-in image of the Peekaboo dwarf in the F606W band from HST with the position of the 1.5-arcsec-width long slit superimposed (similar to that shown in Karachentsev et al. (2023)). We expanded the boundaries of the slit width by 0.7 arcsec to account for the light of the adjacent region which falls to the slit due to the seeing effect. Positions of the discussed hot and supergiant stars (Sect. E) are shown by the small circles with numbers, corresponding to the list in Table E.1. Bottom. Colour (V, I filters combined) image from HST of the Peekaboo dwarf with a similar scale and orientation as the top image. Numerous small (fraction of 1 arcsec) blue non-stellar objects (’nebulosities’) are seen, with the linear sizes of 7–15 pc. Due to the small sizes, they probably are related to singular massive stars. Seven of them are marked as N1–N7 in the top panel. Objects N1–N5 contribute to the emission in the slit.