Medium/large individual server
Homeservers which have more than 1000 Monthly Active Users (MAU) or which see an upload rate of a steady 0.5Hz will fit this category. Other metrics to consider are how many rooms the server is in and how much media is being shared in those rooms. For example, a homeserver may only have a few users on it and a few uploads an hour, but might partcipate in rooms which share gigabytes worth of media every day - those servers might still see a benefit of using this project.
For this deployment, servers will need a reverse proxy which can route media requests to MMR, leaving the other Matrix requests going to the homeserver. More information on this setup can be found in the "Reverse Proxy Setup" section of this documentation.
In this setup it is usually expected that either the Docker image or binaries will be used alongside the process running the homeserver itself. For instance, if you're using Synapse then usually MMR will be running on the same host alongside Synapse.
Normally the system specifications for your homeserver will have enough overhead to also run an MMR instance.
For clarity though: the CPU requirements are usually minimal (1-2 cores), and the memory usage can be calculated per the configuration section of this documentation. The disk requirements can be mitigated using S3 or an S3-like service, or by referencing the configuration section of this documentation.