is there a css way to add an element to featured images in blog posts?

Featured images function like headers in blog posts.

I wanted to add an element to the featured image using CSS.

In a previous thread
https://generatepress.com/forums/topic/can-logo-be-same-line-as-navigation-and-right-aligned-button/

you told me how to insert a page header element. Is there a way to do the same thing for a featured image?
.page-header-content:before {
content: “”;
width: 100%;
height: 100%;
background-image: url(url removed for forum)
background-repeat: no-repeat;
background-size: 100%;
background-position: center bottom;
position: absolute;
}