Google has tried to get Apple to include RCS as part of a cross-platform messaging app
Now here’s the thing. What do you suppose happens in an RCS group chat when an iPhone user joins it? All of those lovely features go away which is exactly what happens when an Android user joins an iOS group chat. Yet, you never hear about Android users bullying iPhone users to the brink of emotional distress. And Google has been more than willing to allow Apple to add the RCS platform to Apple’s Messages app. However, Apple CEO Tim Cook would probably prefer hearing his sink drip all night rather than allow a cross-platform messaging app to be developed.
Google adds the profile picture of the person you’re messaging on the top of the screen
Also, and this is important for Android users to understand, RCS is available on the Google Messages app. It is NOT available on the messaging apps that your carrier might have pre-installed on your Android phone. For example, if you are using the Verizon Messages app, T-Mobile Messages app, or any other Android messaging app outside of Google Messages, you are not getting the RCS platform.
For RCS to work, you and the rest of the chat group must all be using the Google Messages app. You can tell if others you are chatting with are using Google Messages by the color of the text balloon that appears when you send a message. If it is a dark blue, you are engaged in a chat over RCS. Also, look at the text field. If it says Text message, you are about to message an iPhone user or an Android user employing a messaging app that is not Google Messages. Instead of using the RCS platform, such messages use old-school SMS.

RCS to iMessage chat at left, RCS to RCS messaging on the right
How to join the Google Messages beta to receive new features before most of the public
Even if you aren’t a beta tester for the app, you should see the profile pictures appear on an upcoming stable version of Google Messages.