Current state of affairs

When you edit a page with template preview on, list view shows the following:

When you edit a partially synced pattern instance, list view shows:

The problem

The lock icon is not entirely helpful for a couple of reasons:

1. Visual overlap with the user-controlled locking mechanism despite subtly different behavior.
2. Suggests the block is not editable at all which isn't the case.
3. Suggests the block can be unlocked in context which isn't the case.

Is there an alternative to the lock icon?

cc @WordPress/gutenberg-design