Found Unicode related issues and how to address them:

1. Browser is not showing emojis

Solution:
Its a font issue and you have to install a additional font that supports emoji for chromium-based browsers like Chromium, Google Chrome, Opera etc.

• noto-coloremoji-fonts – Noto Color Emoji font
• twemoji-color-font – Colored Emoji Font From Twitter

Alternatively you can add and load the missing font inside your theme header:

@font-face {
  font-family: 'Noto Color Emoji';
  src: url(fonts/NotoColorEmoji.ttf);
} 	

or use it via CDN:

@font-face {
  font-family: 'Noto Color Emoji';
  src: url(https://gitcdn.xyz/repo/googlefonts/noto-emoji/master/fonts/NotoColorEmoji.ttf);
} 	

• CSS Fonts Module Level 3
• Noto emoji fonts

2. Graphemes are not shown correctly in the browser

What is happening here?