The first time the Order Amount field was dragged onto the report, Excel automatically summed it up, called the field Sum of Order Amount, and placed the field title in the upper-left corner of the PivotTable report, just above the Salesperson row field.
When the Order Amount field was dragged onto the report a second time, Excel automatically added it again, and called it Sum of Order Amount2.
Excel also created a new Data heading and by default placed both of the data fields beneath that heading to the right of the row fields. That's just what happens when there's more than one summarized data field in a report.
It takes one more step to turn the second field into the Count of orders instead of the Sum of orders.