Well, trying to describe what a silver certificate looks like based on the provided text is a bit like trying to describe a rock star based on their tour dates. We know they were around from 1878 to 1968 and came in various denominations, from a modest $1 to a whopping $1,000. We're also told they came in two sizes, Large and Small, and were prized for their "intricate designs." That's a lovely, if not terribly specific, description.
Since the provided context is playing it a bit coy with the visual details, let me paint a more complete picture for you. The most tell-tale feature of the common, small-size silver certificates is their bling, or rather, their blue. Unlike the modern green seals and serial numbers on today's dollar bills, most silver certificates sported a distinctive blue treasury seal and matching blue serial numbers.
Beyond the color scheme, the words themselves give the game away. Right above the portrait, you'll often see the prominent declaration "SILVER CERTIFICATE." Furthermore, they carried a promise that today's cash can't make: something to the effect of "This certifies that there is on deposit in the Treasury of the United States of America [X] Dollar(s) in silver payable to the bearer on demand." So, in essence, they looked like a classic U.S. bill that decided to accessorize with blue and came with a receipt for precious metal you could, at one time, actually collect.
