If your choosing the export orders from all gateways, and have chosen to export to contact information also, then you may have noticed that these contact names look a little unusual.
In short, Xero does not allow two contacts to have the same name, and there are two reasons why that's a problem.
The first reason, as you may guess, is two customers have the same name.
The second is if Reconcile.ly tries to create the customer, but you have already created them manually or with another app. Apps use unique ID's to find contacts, so if the old app or the manual process didn't create this, then there is no way for us to know which contact is which.
To solve this, we append the Shopify customer ID to the name, it's a little ugly but works. Xero have stated they are going to change this, but no timeline is set yet.