Doc change: image optimizations for docs.

Change-Id: I33fbdcf11ec7cd6140d287184392866926f05551
diff --git a/docs/html/images/external-display.png b/docs/html/images/external-display.png
index 337aba4..f71d09f 100644
--- a/docs/html/images/external-display.png
+++ b/docs/html/images/external-display.png
Binary files differ