sharper images with more accurate color reproduction than found with today's smartphone cameras. This is because the information found on the three layers is processed down to one virtual pixel, which results in more information per pixel and thus, a better picture.
Anonymous sources say that the sensor on the HTC M7 will resemble the sensor used on the Nokia 808 Pureview. Like the latter device, the HTC M7 will be able to take pictures at higher resolutions when using a special mode. That is similar to the aforementioned Nokia 808 Pureview which heavily promoted the 41MP sensor even though it is available in just one mode. The remaining modes shoot pictures in 8MP. HTC does plans on featuring the Ultrapixel term when advertising its next flagship model.
Earlier rumors about the HTC M7 noted that the device would have a 13MP camera which would actually be very close to the 4.3MP X 3 for the three layers. We should know more for sure on February 19th when HTC holds a press event, presumably to unveil the phone.