On the docs, Casual consistentcy "read your writes" guarantee contradicts the Isolation explanation

The guarantee: https://docs.mongodb.com/manual/core/read-isolation-consistency-recency/#causal-consistency-guarantees

Read your writes: Read operations reflect the results of write operations that precede them.

The Isolation explanation on that same page: https://docs.mongodb.com/manual/core/read-isolation-consistency-recency/#isolation

Operations within a causally consistent session are not isolated from operations outside the session. If a concurrent write operation interleaves between the session’s write and read operations, the session’s read operation may return results that reflect a write operation that occurred after the session’s write operation.

Thses two statements, from what I understand, contradict each other.

If you guarantee that I can read the write that just previously executed (in one transaction),
How can you say, “causally consistent session are not isolated from operations outside the session”?

With RYW, a read can fetch either the previous write in the same session or a write in a different session. That is, to satisfy RYW, a value read is not restricted to the write in the same session.