I originally meant for it to be transparent. I tried making it out of stained glass, but it didn't look quite right. I also tried a mix of stained glass and other things, but ultimately stained clay looked closest to the real thing. Making Murph's room a cube made it easier to slot into my very modular design for the tesseract. I'm also not that good at interior design. I couldn't think of anything else to put in there, so the extra space would have been wasted anyways. I don't really know how I could have shown the time difference, but it's a very interesting idea that I might use for and update later down the road. Thanks for your input!