The $1B of salaries are being taxed as income and the $2.2B of sales most likely hits a sales tax. (Or the $1.2B difference, if it’s a VAT/GST style tax.)
I personally don’t see the point of corporate tax, other than to make other taxes seem smaller than they’d otherwise have to be. Profits are not in and of themselves useful to people; they have to be converted to income somehow.