So whether it’s the copy, whether it’s images, you need to make sure that the whole content is seen so that Google can look at the page and estimate how optimized it is. Otherwise, if you just show some above-the-fold content to Google, that’s not going to be enough.
And what’s important to really get here is that Google doesn’t interact with content, and Google doesn’t scroll. So if you rely on Google to interact with your content or scroll, you will be disappointed because it will just not do that. And a good, really good example of this is when placeholder images are indexed instead of the normal images.
Placeholder image is kind of a dummy image that you would use below the fold to make sure that it’s really light, so it doesn’t impact the loading of the page, or the speed of loading of the page. And then once you scroll as a user, this placeholder image will be switched to the normal image. But guess what? Google doesn’t scroll, so in this situation, what you need to do, you need to make sure that all the images are seen by Google.
So even if you’re using placeholder images, you always need to have a default image URL that Google can go to, grab the image, index it, and so that it can be crawled. So that should be used here in the URL. So image source and then the URL, the URL of the default image, and the location. And then you can always use source to list the image files for different screen resolutions as well.
How to do it right
To sum it up, don’t rely on Google to scroll or interact with your content. And secondly, use the image source and then the default image that Google will see and index, not a placeholder, but a default image.