render full-size image in JNews User List

add_filter( 'get_avatar', 'override_user_avatar', 11, 6 );

function override_user_avatar( $avatar, $user_id, $size, $default, $alt, $args ) {
    if ( 500 === $size ) {

        $profile_picture = get_the_author_meta( 'profile_picture', $user_id );

        if ( $profile_picture ) {
            $image = wp_get_attachment_image_src( $profile_picture, 'full' );

            $class = array( 'avatar', 'avatar-' . (int) $args['size'], 'photo' );

            if ( ! $args['found_avatar'] || $args['force_default'] ) {
                $class[] = 'avatar-default';
            }

            if ( $args['class'] ) {
                if ( is_array( $args['class'] ) ) {
                    $class = array_merge( $class, $args['class'] );
                } else {
                    $class[] = $args['class'];
                }
            }

            $avatar = sprintf(
                "<img alt='%s' src='%s' srcset='%s' class='%s' height='%d' width='%d' %s/>",
                esc_attr( $args['alt'] ),
                esc_url( $image[0] ),
                esc_attr( "$image[0] 2x" ),
                esc_attr( join( ' ', $class ) ),
                (int) $args['height'],
                (int) $args['width'],
                $args['extra_attr']
            );
        }
    }
    return $avatar;
}