The wLcdLayout field is a number value from the CCID USB descriptor:
Number of lines and characters for the LCD display used to send messages for PIN entry.
XX: number of lines
YY: number of characters per line. XXYY=0000h no LCD.
The majority (93,31%) of readers do not have a display so 0 lines and 0 characters per line.
We then have pinpad readers with a display. The most common configurations are 2 lines of 12, 16 or 17 characters.
One reader, VASCO DP865, has a big display with 8 lines and 24 characters per line.
One reader, REINER SCT cyberJack go, is bogus and has XX and YY reversed. The screen has 2 lines of 16 characters and not 16 lines of 2 characters. It is obvious when looking at the reader picture.