A log with words on it. It gets its own page, its own address, and your name on it.
There is no separate review feature. Write something when you log a record, or open an existing log and add it later, and that log is a review.
Line breaks are kept, so use paragraphs if you want them. What you write is public. It shows on the record's page and on your profile.
Every review gets a page of its own, at risocast.com/u/your-handle/review/the-record. It carries the record, your score, the date and your words, at a width meant for reading.
That page is built on the server and makes its own preview image, so a link to it shows the record and the opening of what you wrote instead of a bare URL.
Open the log and edit it. There is one review per record, so rewriting it replaces what was there.