Summarize Notifications is an Apple Intelligence feature that condenses lengthy notification previews.
You can disable Apple Intelligence notification summaries for all apps or select specific apps.
On iPhone or iPad, go to Settings > Notifications > Summarize Notifications and toggle off the switch for Summarize Notifications to turn off all summaries.
On Mac, go to System Settings > Notifications > Summarize notifications and toggle off the Summarize Notifications switch to disable this feature entirely.