When Poe is playing poker, the final "river" card has a binary value in the top left that translates to 4B 53 in hexadecimal code. In the ANSI/ASCII character encoding used by most computers, this is translated to "KS", which probably indicates that the card is a King of Spades.
The A.I. concierge at The Raven Hotel is named Poe. In the poker scene he wears a bowling shirt embroidered with "Edgar A.", as in the writer Edgar Allan Poe (known for the poem "The Raven") on whom he is modeled.