This DLC changes the SpaceEngine license to allow for personal commercial use, and unlocks some "professional" features helpful for capturing video footage and creating space assets for your own projects:

• Camera path editor
  
• Ability to save video and screenshots with transparency
  
• Unlimited resolution for exporting skyboxes, including with HDR DDS cubemap format
  
• Unlimited resolution for exporting planet textures
  
• Unlimited rendering resolution in the fisheye/dome and equirectangular projection modes

Details about commercial usage permissions can be found in the EULA.
Reselling via third party (ie. using the software to create content for re-sale via third parties such as ShutterStock) is expressly forbidden.

Note: unlimited resolution means that SpaceEngine will not restrict you from using any resolution you want, but there are practical limits due to limitations in your graphics hardware. If you have a very recent high-end card, you will be able to use much higher resolutions (e.g. 32768x32768) than you would be able to achieve with older or low-end hardware (e.g. 8192x8192).