a. Those kids were talking as in gangster movies.
b. Those kids were talking as if in a gangster movie.
(Meaning: They were talking the way they do in gangster movies.)
c. The workers in the toy shop were wearing masks and capes, as in superhero movies.
d. The workers in the toy shop were wearing masks and capes, as if in a superhero movie.
(Meaning: They were wearing masks and capes, and in that respect they were similar to people in superhero movies.)
Are the above sentences grammatically correct?
Do they correspond to the given meanings?
In (a) and (b) we're talking about the manner in which something is done. In (c) and (d), the similarity is not really in the manner, but in the simple fact that they were wearing masks and capes. The fact that they were wearing masks and capes is what creates the similarity, but the manner in which the masks and capes are worn is not important.
I want to see if a comma before 'as in' and 'as if in' would change the meaning and turn the phrase from defining (the manner) to non-defining (the very fact is similar and the manner is not even an issue).