The likes action on the river applies to the 'entity' about which the river item was create.

So if a user has a new avatar that would be the user. If a new blog was created it would be the blog.

Since we decided it wasn't logical to have Likes enabled on users and groups there is no Like action on the river activity for these kinds of entities.

Also you (in the Elgg datamodel) can't like a river activity only the subject of the activity. So Liking a new avatar would be the same as Liking that that user joined a group. Therefor if you Liked the new avatar you'd also liked the group join. This isn't what a user would expect.

Hope this explains why it's not possible.

Because of the limitations of activity items they maybe should be upgrade to be entities. That allows liking them for instance. This idea has been mentioned earlier here: https://github.com/Elgg/Elgg/issues/10591

That issue/mention is 5 years old (not that early), what happened?

I know Elgg is a framework and we as developers need to create things with it, but I also think Elgg is more than just a social networking framework, at least could be more.

The majority of users of Elgg use it as it is, as a social networking platform not framework, that's why you guys created so many plugins and added so much features to core...maybe it's time to push even more features...just a friendly suggestion.

I'm just a web designer and soon to be a web developer, I really want to be able to help with this project, but will take time, like your time, which is most important, and not to mention working for free, but it's not impossible.

Thank you very much for building such and amazing platform!! I will dedicate my spare time learning more about php and Elgg to help you guys make Elgg even better. You probably heard these words before...but a scorpio keeps his word...mostly :))

Just felt the need to deviate a bit...sorry!

Maybe it would be best to get in contact with the Elgg core developers directly via email and/or a message here on the site to make them aware that you want to become a reviewer. There are a few requests open at Transifex (for older version of Elgg even!) that haven't been dealt with for years most likely because they don't get any notifications about these request and therefore just have missed them.

You could try a mail to info@elgg.org or maybe a message to https://elgg.org/profile/jdalsem or https://elgg.org/profile/jeabakker.