How to distinguish the donation from the reward in the list of payments received

I try this plugin and I don’t understand how the project creator distinguish the donation payment from the reward payment. If I go on the pledge list I see on table reward and donation but I can see if a user buy a donation or a pledge. For example: If I setup the reward to 10$ and a user donate 10$, how can I understand if he take a simple donation or he buy a reward? I say this because reward can be a fisic product.
Best regards