src/Extensions/Extension.php
public function getIcon()
    {
        if (($icon = $this->getExtensionProperty('icon'))) {
            if ($file = array_get($icon, 'image')) {
                $file = $this->path.'/'.$file;

                if (file_exists($file)) {
                    $mimetype = pathinfo($file, PATHINFO_EXTENSION) === 'svg'
                        ? 'image/svg+xml'
                        : finfo_file(finfo_open(FILEINFO_MIME_TYPE), $file);
                    $data = file_get_contents($file);

                    $icon['backgroundImage'] = 'url(\'data:'.$mimetype.';base64,'.base64_encode($data).'\')';
                }
            }

            return $icon;
        }
    }
public function getIcon()
    {
        if (($icon = $this->getExtensionProperty('icon'))) {
            if ($file = array_get($icon, 'image')) {
                $file = $this->path.'/'.$file;

                if (file_exists($file)) {
                    $mimetype = pathinfo($file, PATHINFO_EXTENSION) === 'svg'
                        ? 'image/svg+xml'
                        : finfo_file(finfo_open(FILEINFO_MIME_TYPE), $file);
                    $data = file_get_contents($file);

                    $icon['backgroundImage'] = 'url(\'data:'.$mimetype.';base64,'.base64_encode($data).'\')';
                }
            }

            return $icon;
        }
    }
Loads the icon information from the composer.json.

@return array|null