Originally Posted by tesseract420
I don't believe it's a KF8 file.
I saw this while reading on the Kindle for Mac app.
I took a look at the same text on the iPhone and instead of a drop cap a large, inline capital letter is displayed.
Interesting how that the behavior is different on different devices.
What you've described is actually proof that it's very likely
a KF8 file: same book displaying differently on different devices/apps. I don't think the iPhone app supports KF8 yet, but I know
the Kindle for Mac app does.
Traditional dropcaps simply can't be done in the older-style MOBIs—unless the entire first paragraph were an image. In which case, you'd be able to tell by increasing/decreasing font-size.