The two eink Kindles that support KF8 both have line heights larger (KF8 only) then what is display in the screen grab. So because of this, that cannot be a screen grab from an eink Kindle.
Gotcha. I just couldn't see how that was relevant to Tesseract's "how are they doing a dropcap in this
Amazon book?" question. I still
don't understand why it would be relevant, to be honest. The answer is; "it's a KF8 or Topaz ebook, where dropcaps are possible." And the fact that the same ebook renders differently on different devices/apps strongly suggests KF8—since Topaz would likely render consistently across all Kindle devices/apps.