Question about /uploads/bb-theme

I have a question about wp-content/uploads/bb-theme

According to this page:

The files in here are the default skin files. However, I have two relatively fresh copies of WP with Beaver Builder latest version and the files in one do not match what is in the other.

If these are the ‘default’ skin, I would expect them to agree but there are numerous differences.

What do these files truly represent?