I know only the very basics of the ancient Egpytian "stars" (or deities), thanks for clarifying this.

I see Harsomtus as Horus avatar is sometimes depicted with a twin horn:
[en.wikipedia.org])

I missed to point out the detail photo of the rectangular Zodiac in the Hypostyle I was referring to. It's [EGYPT 29527] on this page: [paulsmit.smugmug.com]

In that German forum, Michael translated the flower-snake's small other name plate, which is visible in the other photo, the Zodiac relief, in the same way as you (Uniter of the Two Lands on his barge.):

Ra-smA-tA.wj Hrj-jb Jwn.t
"Re, der die Beiden Länder vereinigt, der sich inmitten von Dendera befindet"

But I'm confused as the snake is typically Ra's enemy Apophis he is facing potentially during each night. Or which detail in the snake symbol distinguishes the Apohpis snake from the Harsomtous snake?

About my interpretation from the poster: That's mainly about an alternative interpretation of the sun-ray bundle as comet stream. The flower-snake is secondary, but in my interpretation could be related to a special individual comet as comets' tails usually look like snakes as they wiggle within the solar wind and change their appearance in detail within a few minutes sometimes.

Last week comet Leonard was a nice example for that with its unusual long tail of up to 60° visually as seen from Earth under perfect viewing conditions: [apod.nasa.gov]