Just as you need to add activity type columns in your activity section on your various layouts, you will need to add those fields to the actual activity view to see them when viewing more information about activities. This helps users differentiate between shares, views, and downloads.
The following instructions require an appropriate Salesforce role to allow for editing layouts.
In this example, we are in an opportunity layout. In any Opportunity in the Activity History section, click on any existing activity.
In the upper right, choose Edit Layout.
From the field section, drag and drop Share Activity and Share Recipient Data into the Task Information section.
Remember to save your changes!
Now in the detail view of an Activity, you will see this information.