Here's the third chapter illustration and a blurb from the story for context.
"Another little laugh left Gleaming as she drew Thunder away with her wing towards the door. With a hoof, she pushed the door open to reveal a gigantic room bathed in a deep golden glow. Thunder once again braced himself for sensory overload as he was let inside. The store would have well been classed as its own section of the mall on its size alone! It was four stories high with numerous shelves, displays, toy racks and even had play areas with soft padding.
Even now Thunder still found himself amazed at the size of the things these ponies built."