If only an adjustment with CSS is possible to place an image at a certain position, the solution via :after pseudo element is the best.
.theimage:after {
background-image: url('/images/bild.png');
background-size: 10px 20px;
display: inline-block;
width: 10px;
height: 20px;
content:"";
}
Alternative with ‚mask‘:
.elementor-post__read-more:after {
width: 20px;
height: 14px;
display: inline-block;
content: '';
mask: url('data:image/svg+xml;charset=utf-8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 7.53 5.95" xml:space="preserve"><path d="M4.505.008a.16.16 0 0 0-.094.166c.007.04.171.208 1.309 1.348l1.301 1.302H3.57c-3.439 0-3.451 0-3.492.025A.186.186 0 0 0 0 2.981c0 .012.009.04.021.064.041.087-.266.08 3.546.08h3.454l-1.3 1.302c-1.359 1.36-1.333 1.332-1.309 1.412.013.042.067.095.108.104.092.02.039.069 1.546-1.436.861-.859 1.436-1.442 1.447-1.467.014-.033.015-.052.004-.094-.013-.048-.166-.205-1.454-1.494C4.696.084 4.621.011 4.574.006a.208.208 0 0 0-.069.002"/></svg>') no-repeat 50% 50%;
-webkit-mask: url('data:image/svg+xml;charset=utf-8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 7.53 5.95" xml:space="preserve"><path d="M4.505.008a.16.16 0 0 0-.094.166c.007.04.171.208 1.309 1.348l1.301 1.302H3.57c-3.439 0-3.451 0-3.492.025A.186.186 0 0 0 0 2.981c0 .012.009.04.021.064.041.087-.266.08 3.546.08h3.454l-1.3 1.302c-1.359 1.36-1.333 1.332-1.309 1.412.013.042.067.095.108.104.092.02.039.069 1.546-1.436.861-.859 1.436-1.442 1.447-1.467.014-.033.015-.052.004-.094-.013-.048-.166-.205-1.454-1.494C4.696.084 4.621.011 4.574.006a.208.208 0 0 0-.069.002"/></svg>') no-repeat 50% 50%;
-webkit-mask-size: cover;
mask-size: cover;
margin-left: 7px;
background-color: #d51030;
transition: all .3s;
}
.elementor-post__read-more:hover:after {
background-color: #000;
transition: all .3s;
}