Learn Editor: Update policy-keys-overview.md

Author: garrodonnell

articles/active-directory-b2c/policy-keys-overview.md

@@ -77,15 +77,16 @@ If an Azure AD B2C keyset has multiple keys, only one of the keys is active at a
 - When the current key's expiration time has elapsed and the key container *does not* contain a new key with valid *not before* and *expiration* times, Azure AD B2C won't be able to use the expired key. Azure AD B2C will raise an error message within a dependant component of your custom policy. To avoid this issue, you can create a default key without activation and expiration dates as a safety net.
 - The key's endpoint (JWKS URI) of the OpenId Connect well-known configuration endpoint reflects the keys configured in the Key Container, when the Key is referenced in the [JwtIssuer Technical Profile](./jwt-issuer-technical-profile.md). An application using an OIDC library will automatically fetch this metadata to ensure it uses the correct keys to validate tokens. For more information, learn how to use [Microsoft Authentication Library](../active-directory/develop/msal-b2c-overview.md), which always fetches the latest token signing keys automatically.
 
-![A diagram describing the process for key rollover in Azure AD B2C.](media/policy-keys-overview/key-rollover.png)
+:::image type="content" source="media/policy-keys-overview/key-rollover.png" alt-text="A diagram describing the process for key rollover in Azure AD B2C." lightbox="media/policy-keys-overview/key-rollover.png":::
+
 
 ## Key caching
 
 When a key is uploaded, the activation flag on the key is set to false by default. You can then set the state of this key to **Enabled**. If a key enabled and valid (current time is between NBF and EXP), then the key will be used.
 
 ### Key state
 
-The activation flag property is modifiable within the Azure Portal UX allowing admins to disable a key and take it out of rotation. 
+The activation flag property is modifiable within the Azure portal UX allowing admins to disable a key and take it out of rotation. 
 
 ## Policy key management