Skeleton Screen on page load

I understand there is a skeleton screen pattern that displays a page outline when the page loads. What is the name of the pattern and where do I find more info on it?

Are you asking for web or mobile? Are you looking for a splash screen?

Desktop. 

Skeleton screen idea here:

My understanding is that the skeleton screen for Outsystems is based on an image. This example below is in CSS. So to expand on the question - can I implement it in CSS instead of an image

https://css-tricks.com/building-skeleton-screens-css-custom-properties/