If you still think that the best place to have a roleplaying encounter is inside your head then I will wholeheartedly agree. Nothing can beat a good imagination when it comes to special effects and getting even the most minute detail just right. So what arguments can be made for visual aids?
This is something I recently cobbled together for my group, and maybe you can make use of the idea as well. For us, it all started with a mysterious ship from which emanated an eery blue light. I had the miniature already picked (a ghost beholder, but don’t nail me on the precise name) and I used this simple led setup to make it glow.