From my understanding is that snapshot replication accours at a specific time, same logic goes to screenshotting at a specific time. The data will not change as times goes for that snapshot replication. But for read replica, the data is being updated over the time

The read replica generally receives the data in live traffic with a delay between the write operation and the same updated data being available in the read replica. For example, in MongoDB (NoSQL), the read replica is updated almost at the same time as a write operation...