Income paid to employees allows the employer to use that as an offset to income earned by the company. That part is correct.
Trump and company's problem is that income was never taxed.
And to add to Trump's problems Medicare and Social Security are trust fund obligations that must be paid by the employer.
Enter Ivanka and her side consulting business. She can not be a principal employee and a 1099 consultant to avoid Medicare and Social Security taxes. So now the company will be on the hook for the entire tax which is normally paid by both employee and employer.
And of course having her hair done etc doesn't quite cut it since that should be her expense.