This symbolises measuring the feet of Hermes. Which is “dactylic hexameter” for Homeric hymn 4.

Homeric hymn 4 is also a massive part of room 20 and the turtle/tortoise.

The twin snakes are Hermes’ staff Caduceus but missing the wand/staff and wings/feathers. I wrote in room 20 how it is about Homeric Hymn #4 (which is “dactylic hexameter”, like Iliad/Odyssey). In HH4 Hermes creates the first lyre from a tortoise and eventually gives it to Apollo who gives him Caduceus.

Now we need “dactylic” and the missing feathers for Caduceus. Well, the bird looks like a pterodactyl with feathers. As a prefix “ptero-” means “having wings”. So we move can move the ptero- off the bird for “dactyl” and for the wings/feathers of Caduceus.

For the missing wand/staff I’m not sure yet. The blind man in room 29 seems to hold it.

Because we’ve been seeing a lot of “count things in the room, find the number of the door you want” suggestions, though, I do want to emphasize that you will almost always be able to find ways to count small numbers in every room, and it generally just doesn’t seem plausible to assume you’re intended to find the one right way to count things to get a specific answer.

If there were 44 of something in the room, or 4 of something with 11 parts, something like that, it would seem a lot more intentional, for obvious reasons. But you can likely look around whatever room, vehicle, outdoor area, or space station you’re on right now, and find multiple ways to count to 4.

Counting things can be twisted to mean anything you want. It’s not the way.

a bird’s song
a [phone] number
a name
uh….
roll
curtain
the toll-free 888 area code (this is assuredly the one)