@abhinavashu what @Mr_nobody says is true...it is just a procedure. If there is a document out from the ordinary, it has to be reviewed by an officerI don't know very much how it works for self-employed applicants. But, I don't think there is a big issue. It seems to me that you have submitted all the necessary docs.
I am sure that more than 95% of applicants are employee and the analysts learned how to deal with these cases. But your case was different. I am sure the analyst didn't know what to do and decided to flag it for other seniors.
From your perspective, I think you already did what you can. If you know there is any document that can help them verify your self-employment, send them. Otherwise, you need to wait for them to pick up your file and check it.