When another parker reports you in their space, the Parkable app updates your booking to that space and reallocates the other parker to your original space in the app.
For example: your original booking was in bay B54, you accidentally parked in B71 that was booked by someone else. The other parker reported that someone was in their space, B71. The Parkable app has now swapped your bays so you both have somewhere to park and don't need to move your cars!
The automated email is a reminder for you to check that you've parked in the correct space in the future.