WHAT ARE THESE SYMBOLS AND WHAT DO THEY MEAN?!

Yeah, that's Daedric, the troll language.

For the picture you posted, the letter-by-letter thing says "Ynam ton tub," which reversed is "But not many," since it comes right after the text which says "Years in the future."

I do too much research on this stuff. ._. But yeah Daedric is just different letters, and then everything's written backwards.

it`s called trollian. i don`t understand it either!

It's the Daedric Alphabet, but in Homestuck it's called Trollian and is used to represent the Troll language.

There's a List of Daedric Alphabet insertions in Homestuck on this website:

link

They mean wwhat they mean.

It says "But Not Many..."

Ynam ton tub