Sometimes we don't need to leave a comment as a reply to our colleagues at work because it just requires a "ok" or "yes". So in this case, that would be awesome be leave a reaction to the comment of our colleagues.

Example:

Comment: 'Thanks, I'll be checking that for you'

Reaction: 👌

Nowadays, if we don't comment after our colleagues' comment, it looks like we didn't see their comment but we saw but it doesn't require a new comment, just a simple reaction that means: 'great, move forward' which is a 😉.

It's important to notify the colleague who elft the comment about the reaction, an additional feature would be a 'notify my colleague about my reaction'.