If a card has prioritized cards within it, the number of them will show on the front of the card wherever it appears, with an exclamation mark. For example, a card with two priorities within it will display '2!' on its face.
If you click this small number, you will enter 'priority mode'. In this mode, the first priority within a card will show up in front of it (on the grid). This will allow you to see priorities "prior to" the card they are within. This is very useful for seeing the next action within a project. If the first priority also has a priority, that will cover the parent priority, making it easy to find the next action even within a nested subproject.
Priority mode might not make it into ao-svelte.