The app may take a few minutes for the update, depending on the network speed etc. Once the app update begins, you can see a red dot on the Menu icon (top right corner of the app screen).  

On tapping the menu, the Red Dot leads to the Notification section which indicates the status of downloads. The red dot disappears on successful completion of app download. On Failure, the Red dot continues to be displayed. 

How to see the status of the update?

You can see the status of the update in the Notifications section, where it displays the progress of the various resources that are getting downloaded. The Notifications sections indicates if the download has failed and where it has failed: e.g. Downloads Failed : Extended Image Set

Screenshot: Red dot on the Menu button to indicate update in progress

Screenshot: Red dot on Notification section 

Screenshot: Notifications section indicating status of resource downloads during app update