Hey @patrick ! Great questions! Here is how it works:
- Once an item is added to the cart, we “open a cart” and it gets a “Cart ID”
- We “tag” a cart as “abandoned” 1 hour after it was first opened if it was not completed (we allow 1 hr to complete the purchase, before we tag “abandoned”)
- If we have the details of the customer - either beacuse he is a logged in member or beacuse he completed the first phase of checkout and clicked continue (where he enters his email) - we will send him an email after the specified time (1 hr from adding the first time + X amount of time you defined in the automation)
An important thing to note when testing yourself:
(a) If you currently have items in your cart you would need to COMPLETE the checkout so the cart gets a new ID, and countdown to “abandoned” can start fresh ( REMOVING wont help, it’s still the same cart ID) - I know it’s a bit annoying for testing, but real customers would not have this issue 
(b) Make sure you clicked “continue” on the first phase in checkout \ your logged in member (so we have an email to send the email to)
(c) Make sure you are not using an “unsubscribed” email - we have a mechanism that right before the abandoned cart email is sent, we verify recipients didn’t unsubscribe at some point - if they did - email is not sent)
We also have a KB article that explains some these, which we will publish once we complete rollout (very soon) - but you can take a look here: https://support.wix.com/en/article/sending-emails-to-customers-who-abandon-carts-in-wix-stores
Hope this helps - feels free to write back for any further questions \ explanations!