You may notice that your activity feed shows more information when viewed on your desktop versus when viewed using the HubSpot mobile app on iOS or Android.
On mobile, only CRM email activities are shown in your activity feed, such as email sends and opens. Other activities, such as lead revisits and document views, won't be shown.
Here is an example of what your activity feed would look like on your Android device:
And on your iOS device:
And here's what your activity feed would look like on your desktop, which includes CRM email information in addition to other activities such as document views and lead revisits (if enabled):