Macaroni, the name of pasta in any of various hollow shapes, is now used to describe people who are impressive in appearance but disappointing in substance. It’s similar to the English saying “Many a fine dish has nothing on it” or the Chinese idiom “embroidered pillow,” which boasts a beautiful cover, but with only worthless dried straw stuffed inside.

形状各异的意大利“通心粉”现在被用来形容那些外表光鲜亮丽而实质一无是处的人。它在这里表示的意思跟英语俗语“虚有其表”和汉语中的“绣花枕头”的意思一样，“绣花枕头”外表很漂亮，可里面却只是填满了干草而已。

For example:

- Hey, do you see that guy over there? He is so hot!

哎，你看见那边那个家伙了吗？他好帅啊！

- Hope he is not a macaroni person.

希望他不是个通心粉才好。