Ghost/ghost/admin/app/components/gh-member-avatar.hbs

<figure class="gh-member-gravatar {{@containerClass}}">
    {{#if this.avatarImage}}
        <img class="gh-member-avatar-image" src="{{this.avatarImage}}" alt="{{or @member.name @member.email}}" />
    {{else}}
        <div class="gh-member-initials flex items-center justify-center br-100 {{@containerClass}}" style={{this.backgroundStyle}}>
            <span class="gh-member-avatar-label {{or @sizeClass "gh-member-list-avatar"}}">{{this.initials}}</span>
        </div>
    {{/if}}
</figure>