The answer to your question is that the example represents a "sloppy" sentence construction, but one which has become (unfortunately) commonly accepted by the majority of Western English speakers. My objection centers around the use of the word "like", which has become almost universally substituted for more definitive speech. A typical modern sentence contains clauses such as "I was like, you know, ashamed of what you said". An English speaker 200 years ago might have used the construction "(your behavior/statement) was like unto that of a shy teenager"....but of course, English has evolved/devolved away from more complex grammatical structure to a more "text-speak" form. A quicker fix to your original example: "Don't be ashamed. It was cute, like a shy teenager would act/be". This is because the original intent of "like" in your example is to set up a comparison with something else. Without further clarifying what "it" was, you've just got "like" dangling out there without defining what comparison the speaker is trying to convey.