Reword progressive comment in tests/CMakeLists.txt
diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index f08c896..be6f82e 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -231,7 +231,8 @@
set_property(TEST test_cmd_metadata PROPERTY DISABLED True)
endif()
- # Only aom encoder supports AV1 progressive encoding.
+ # Only aom encoder supports encoding AV1 spatial layers (used to implement
+ # AVIF layered images that can be progressively decoded).
set_property(TEST test_cmd_progressive PROPERTY DISABLED True)
message(STATUS "Some tests are disabled because aom is unavailable for encoding.")