by not lazyloading the image (somehow I think we have discussed this before)? 🙂
@optimizingmatters It would be helpful for those of us who’ve already spent days searching for you to take a couple of minutes to make a more comprehensive response on preloading LCP images.
LCP images will get flagged by that message if (a) they are lazyloaded or (b) they are background-images. both (a) and (b) are loaded with low(er) priority by browsers, hence GPSI (since a few days) recommending to preload those images. AO currently cannot fix that for you as AO does not *know* which image ends up being the LCP one though.
The best solution is to ensure above-the-fold images are not lazyloaded (the AO lazyload settings can help, but Zo is using another lazyloader) and for background-images to manually add something like <img src="<!--image url here-->" style="display:none;"> to try to “fool” th browser into loading the image with higher priority.
It is not impossible AO will have a solution for this in the context of CriticalCSS (as criticalcss.com should be able to identify above-the-fold-images).
hope this helps,
frank