Showdown in the Shadows: Part 2 - S2-E48
Continuity mistake: When Kaiba is on his computer and discovers the Winged Dragon of Ra's secret special power, there is an image of the Winged Dragon of Ra card on his monitor screen. A rectangular white box appears on the monitor, covering the bottom right corner of the dragon card. In a closer shot of the monitor, it is now switched; the corner of the dragon card is now covering the rectangular white box. (00:10:15)