I've tried decrypting them myself to little avail, I think it starts with "I'm here" but after that I get lost. Are these the original codes used in "The Adventure of the Dancing Men"?

I've tried decrypting them myself to little avail, I think it starts with "I'm here" but after that I get lost. Are these the original codes used in "The Adventure of the Dancing Men"?

I actually looked into this last night after watching it, as I hoped it was an easter egg or message to viewers, but sadly no. It's directly quoted from the original short story "The Adventure of the Dancing Men", by Sir Arthur Conan Doyle.
Holmes held up the paper so that the sunlight shone full upon it. It was a page torn from a notebook. The markings were done in pencil, and ran in this way:
Holmes examined it for some time, and then, folding it carefully up, he placed it in his pocketbook.
"This promises to be a most interesting and unusual case," said he. "You gave me a few particulars in your letter, Mr. Hilton Cubitt, but I should be very much obliged if you would kindly go over it all again for the benefit of my friend, Dr. Watson."
In short, it's a substitution cipher, where each letter of the alphabet is represented by a different dancing man, and the men holding flags denote the end of each word.
AM HERE. ABE SLANEY.
As far as I remember, it was a secret code devised between the main female character of the story and the antagonist Abe Slaney in childhood, and he followed her from America to England where the code began to reappear, hence Holmes's involvement in the case.