Which image describes the Tabernacle ceiling or roof as mentioned in the Book of Exodus, and what verse explains that? Was it straight or pointed?
According to the details in Exodus 26:15-30, it seems like the overall structure of the Tabernacle of Moses was covered with a flat roof. Whether there was an inner curtain that formed a pointed ceiling underneath the flat roof (because a ceiling is found below a roof), I could not say.
Both the NIV and ESV Study Bible diagrams show the Tabernacle Tent (which housed both the Holy Place and the Most Holy Place) with a flat roof. The NIV and the NLT confirm that the upright frames were locked together with horizontal crossbars to form a three-sided rectangle with an open end.
26 “Make crossbars of acacia wood to link the frames, five crossbars for the north side of the Tabernacle 27 and five for the south side. Also make five crossbars for the rear of the Tabernacle, which will face west. 28 The middle crossbar, attached halfway up the frames, will run all the way from one end of the Tabernacle to the other. 29 Overlay the frames with gold, and make gold rings to hold the crossbars. Overlay the crossbars with gold as well. 30 “Set up this Tabernacle according to the pattern you were shown on the mountain.” (see also Exodus 25:9, 40; 27:8)
I’m going with your first image.