From top to bottom, some of the notable changes are: the bar with the name of the token extends across the entire width of the card, the art window is no longer rounded at the bottom, the designation "Token" has been added in front of "Creature" on the type line, and the collector's number, copyright information, and artist's name (in this case, Wayne Reynolds) are printed on a solid black background
Grid Monitor is larger than Reclusive Wight and shuts down your ability to cast other creatures
Tools like PriceCharting are fantastic for this, as they aggregate sales data from eBay to show you current market values and historical price trends for your specific cards
Apart from the 5 basic lands, a Commander deck may not contain double cards and in the card selection for the deck you are also limited to the colors of your commander
Starting with Edge of Eternities, events like this will be the method through which Commander Play Party promos are distributed