Fix wording a bit

docs/alternative-architectures.md

@@ -21,6 +21,6 @@ matrix_architecture: "arm32"
 
 ## Implementation details
 
-For `amd64`, prebuilt images are used everywhere (because all images are available for this architecture).
+For `amd64`, prebuilt container images (see the [container images we use](container-images.md)) are used everywhere, because all images are available for this architecture.
 
 For other architectures, components which have a prebuilt image make use of it. If the component is not available for the specific architecture, [self-building](self-building.md) will be used. Not all components support self-building though, so your mileage may vary.

docs/self-building.md

@@ -2,13 +2,14 @@
 
 **Caution: self-building does not have to be used on its own. See the [Alternative Architectures](alternative-architectures.md) page.**
 
-The playbook supports the self-building of various components, which don't have a container image for your architecture. For `amd64`, self-building is not required.
+The playbook supports self-building of various components, which don't have a container image for your architecture (see the [container images we use](container-images.md)). For `amd64`, self-building is not required.
 
 For other architectures (e.g. `arm32`, `arm64`), ready-made container images are used when available. If there's no ready-made image for a specific component and said component supports self-building, an image will be built on the host. Building images like this takes more time and resources (some build tools need to get installed by the playbook to assist building).
 
-To make use of self-building, you don't need to do anything besides change your architecture variable (e.g. `matrix_architecture: arm64`). If a component has an image for the specified architecture, the playbook will use it. If not, it will build the image.
+To make use of self-building, you don't need to do anything besides change your architecture variable (e.g. `matrix_architecture: arm64`). If a component has an image for the specified architecture, the playbook will use it directly. If not, it will build the image on the server itself.
 
 Note that **not all components support self-building yet**.
+
 List of roles where self-building the Docker image is currently possible:
 - `matrix-synapse`
 - `matrix-synapse-admin`