Describe the bug
Instead of set the loading spinner for img tag
.${this.className}.loading {
background-image: url(${this.#dataUri});
background-repeat: no-repeat;
background-position: center;
background-size: ${this.#size};
background-color: ${this.#backgroundColor};
}

would like to set this for the img's pseudo-elements :before or :after
.${this.className}.loading:after {
background-image: url(${this.#dataUri});
background-repeat: no-repeat;
background-position: center;
background-size: ${this.#size};
background-color: ${this.#backgroundColor};
content: '';
display: block;
position: absolute;
z-index: 2;
top: 0;
left: 0;
right: 0;
bottom: 0;
}
