Chrome native lazy loading images not working

Locally using Chrome 76.0.3809.100 I can see the native lazy image loading work fine, without flag changes. However, it doesn’t seem to be working for WebPageTest agents -

Wondering if this is related to headless Chrome.

FWIW, Chrome isn’t actually headless when run on the Linux agents (it runs in an XVFB virtual desktop for Windows but as far as Chrome knows it is a full desktop window). Maybe one of the flags for running in the test environment is turning off the feature.

Adding [font=Courier]–enable-features=LazyImageLoading[/font] to the Chromium Command-line Custom options works:

Hot damn! I’ve heard native lazy loading was planned for Chrome 75…so it’s officially supported now?