Surprise, it appears the 830 might have a Pureview camera after all- 20MP one, the same as 930/1520 has.
That would give N/MS a competitive mid-range phone with an amazing picture quality.
We can take note of the specs visible in the images, such as microSD support, dedicated camera button and LED flash, and we have been told that the device supports NFC and wireless charging (although this may be supported as an add-on, rather than integrated), Additionally, the 830 will feature 4G LTE support and use a nanoSIM.
Based on where we obtained these images, it seems the device is quickly approaching release and should be announced in the near future; the phone will be part of a global release. As with all new Windows Phones, expect the Lumia 830 to ship with Windows Phone 8.1 GDR 1 which includes support for folders.