Apply suggestions from code review of branch jpeg-capture-in-stacking

Co-authored-by: Beth Probert <beth_probert@outlook.com>

hardware-specific-tests/picamera2/test_acquisition.py

@@ -11,6 +11,11 @@ from openflexure_microscope_server.things.camera.picamera import StreamingPiCame
 
 @fixture(scope="module")
 def client():
+    """
+    A pytest fixture that initialises a test client for the StreamingPiCamera2 Thing.
+    This fixture sets up a ThingServer, registers a StreamingPiCamera2 instance at the
+    "/camera/" endpoint, and provides a ThingClient for interacting with it during tests.
+    """
     server = ThingServer()
     server.add_thing(StreamingPiCamera2(), "/camera/")
     with TestClient(server.app) as test_client:
@@ -30,13 +35,20 @@ def test_jpeg_and_array(client):
     Check that grabbing a jpeg from the stream results in the same size
     image as a array capture or a jpeg capture.
     """
+    # Grab a jpeg from the stream
     blob = client.grab_jpeg()
     mjpeg_frame = Image.open(blob.open())
     assert mjpeg_frame
+
+    # Capture a jpeg
     blob = client.capture_jpeg(resolution="main")
     jpeg_capture = Image.open(blob.open())
     assert jpeg_capture
+
+    # Capture an array
     arrlist = client.capture_array(stream_name="main")
     array_main = np.array(arrlist)
+
+    # Verify image sizes are the same
     assert mjpeg_frame.size == jpeg_capture.size
     assert array_main.shape[1::-1] == jpeg_capture.size