When the markup is provided to obtain the dimensions, and the markup is rendered into the various viewports, the layout shift should be captured at each viewport and then summarized once the calculation has completed. Then when loading up the optimized markup in the preview, the calculation should be performed again. This can then be used to show how much layout shift savings is gained.
When the markup is provided to obtain the dimensions, and the markup is rendered into the various viewports, the layout shift should be captured at each viewport and then summarized once the calculation has completed. Then when loading up the optimized markup in the preview, the calculation should be performed again. This can then be used to show how much layout shift savings is gained.