Under the Social reactions section you can choose what reactions you want to appear:
None: You might just want to add commenting to a list item so you can leave this option selected.
React: Lets users select one of four reactions: Like, Love, Insightful, and Celebrate.
Helpful: Lets users indicate whether they thought something was good or needs improvement.
To turn on the comments feature, select the Enable commenting option.
To prevent certain list items from being commented on, you can select the Turn off commenting and reaction for specific list items option and then select the property from the boolean list.