At the moment the Covers styles are updated whenever the block's attributes change, and it looks a bit weird especially because some attributes are only available for certain styles. Also at the beginning it just shows an empty message which is not very useful to know what the block will look like with data... It's not a blocker, but it would provide a nicer editor experience The current implementation also seems to be causing a lot of console warnings, due to missing keys.

We can look at the Submenu block for how to use block examples for styles!