When creating an invoice you have the option to choose a Simple Invoice or a Normal Invoice.
A normal invoice will display a breakdown all of the charges by line item. See Screen shot below.
A simple invoice WILL NOT show a breakdown of all charges. It will only display the description of work performed. See screen shot below.
To make a simple invoice, go into edit mode of the client invoice and select the 'Use Simple Invoice' option.
Go back into view mode by selecting 'Switch to View Mode'
Select 'Send Client Invoice' and hit 'Refresh Invoice' to download a new PDF of your Simple Invoice.