This is an optional feature which you can turn on and off in the 7.2.1.1 Administration Settings. 

1. Order/Proposal

If you have turned on this feature the proposal will look like this until you have checked the Approval checkbox (Please see below). Ideally you build an approval workflow around this feature to ensure that a second set of eyes have checked the data for example high discounts. Read here how to do this: 7.4.2 Manage Approvals.

2. PreInvoice/Invoice

Invoices are working similar to Proposals. But unlike Media Campaigns we have no approval field but display the "Draft" watermark on invoice records which are in status "Draft", "Reviewed", or "Created".