What is happening to my shell?

I open up the shell, type sh as a test, and here is what I get:

\[\]\[\]\[\033[01;34m\]\w\[\033[00m\]$ \[\]

What does this mean and why is it happening?

Repl link (not my Repl): https://replit.com/@STANISLAVSAPDYI/fighr

dash (from /bin/sh) doesn’t support using \033[ colour codes in the prompt so it prints them as is. It’s some side effect of replit.nix being removed from the Python template.
If you run in Shell:

nix-editor -ha ''

then sh from the bash package take precedence over dash and then when you run sh, it essentially does a set -o posix