Why does the XP40-TTA/DC has a better/ higher resolution than the XP70-TTA/DC?

Why does the XP40-TTA/DC has a better/ higher resolution than the XP70-TTA/DC?

It may be noticed the HMI catalog that the XP40 has a 800x480 resolution while the XP70 model has a  640x480 resolution. This may seem counter-intuitive since the XP70 is the larger screen. See the below explanation of why it is this way.
  1. The original development of XP Series included 5.7”, 8.4”, 10.4”, 11.2” and 15” panels, but not the 7” panel. Original development was completed in 2010 for the XP line.
  2.   The 7” was developed in 2012 to have a better screen (wide screen), higher resolution,  and better LCD hardware.