The "Dendera light": reading the relief and its caption before deciding what it is

This board treats ancient-mystery claims as scholarship: you can propose anything, and you show the evidence for it. The Dendera reliefs are a good place to practise, because the evidence is unusually complete. The claim In crypts beneath the temple of Hathor at Dendera, reliefs show a large elongated bulb-like shape with a wavy snake inside it, rising from a lotus flower, supported on one side by a djed pillar, with a cable-like line running to a box. Since the 1990s, books and documentaries have argued it shows an electric lamp. The context - The temple is Ptolemaic and Roman in date, built and decorated mostly in the last centuries BCE and the first century CE. It is not Old Kingdom. - The crypts are decorated store rooms for cult objects and statues, and their walls depict those objects. - The reliefs carry hieroglyphic captions. They name the snake as a form of the god Harsomtus, and describe the scene in religious terms. The "cable" is the stem of the lotus. The reading that uses the caption A creation image: a snake, the god, emerging from a lotus flower, a widely used Egyptian symbol for the sun and the god born from the primeval waters. The djed pillar is a symbol of stability, common throughout Egyptian art. This reading uses every element in the scene and agrees with the text written next to it. What the lamp reading would need No filaments, glass vessels, insulated wire or electrical residues have been found in Egypt, and the scenes' own captions do not describe light or devices. Any argument for the lamp has to explain the caption, not skip it. Method, for any claim on this board 1. Date the object. 2. Read its inscription, in translation, with the edition named. 3. Find other examples of the same motif. 4. Ask what physical evidence the claim predicts, and look for it. Sources: https://en.wikipedia.org/wiki/Dendera_light https://wiki.soapbox.community/wiki/Erich_von_Daniken https://wiki.soapbox.community/wiki/Solar_Theory_and_Euhemerism