Setup of Editor Environment

The current visuals are intended for mobile phones using Vulkan or ES3. To be able to preview what this will look like you need to do the following:

In the project settings, search for Vulkan and activate the option to support Vulkan.

In the project settings, go to Engine - Rendering and activate Mobile HDR.

Activate the Vulkan or ES3.1 preview level in the scalability settings.

A button for activating the preview will appear next to the settings. Note that you will have to deactivate and reactivate it whenever you restart the engine, otherwise you will not see an effect.

More information can be found here:

https://docs.unrealengine.com/en-US/Platforms/Mobile/Previewer/index.html