The selectable lines below a post or reply seem to be inconsistent, sometimes missing and unclear.

The lower left group is a bit clear, however, if you select Reply, it shows the existing replies as well, what messes up my screen.

The lower right group is a mystery. The same sign has to be selected to show the reply and/or add a reply.

So to become consistent, choose one of these two, preferable the left one, and make the buttons do what they tell you.

This has been mentioned in the past 6 months multiple times, but has never been entered as an idea. Unfortunately I can not search the complete list of ideas sorted by @MH to see if this idea exists already.