好像是词典的解释
原句可以这样看:
To label or mark (with or as if with) a brand.
To label or Mark with, or as if with, a brand.
等价
To label or mark with a brand, or as if to label or mark with a brand.
补充：
如果要具体分析的话，就涉及到插入并列和追加并列的知识，这两个点，这个论坛好像很少涉及。而且实际上以前有一些例句应该分析为插入并列（interpolated coordination），也没有人这样分析。
这句话最常见最好理解的表达形式是
To label or mark with a brand, or as if to label or mark with a brand.
or是并列连词，后面可缩减的自由度比较大，进行缩减：
To label or mark with a brand, or as if with a brand.
把它移到句子中。，并且共用一个介词补足语（介词宾语）就得到，
To label or mark with, or as if with, a brand.
中间也可以不写逗号
To label or Mark with or as if with a brand.
