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A friend wanted to know what I was doing so sent a message with this question: 你在干吗呢, then immediately corrected herself by typing: 你在干嘛呢. I found it interesting that Google translate seems to do a better job translating the first sentence.
What are the differences in actual meaning between these sentences? Is there enough of a difference that a correction is needed?
I've looked at some related questions such as Connotation of 吗 questions vs. affirmative/negative questions, which has helped some, but I'm still not sure in this case.