Thanks for your kind words! Plate-solving refers to the process of looking at the pattern of stars in an image, and attempting to match it against a star catalogue in order to work out the celestial coordinates of the image. We use a piece of software called astrometry.net to do this. However, the software takes a few minutes to run, and newly uploaded observations join a queue to be processed, which means there is a delay between you uploading an image and the celestial coordinates appearing in the associated metadata.
When the plate-solver finds a match, you should see a panel to the right-hand side of your image with a tick-box “Enable overlay”. This will overlay a star chart over the top of your image.