As leaked on their official Twitter handle, The Z mini reportedly sports an 8.0 MP front camera with flash, and 13MP back camera, also with flash. With a 5″ Super AMOLED Display, running an octacore processor,and Dual SIM.
Tecno has been fond of consistently releasing devices.

Android Enthusiasts. The latest piece appears to be such a delight with promises of greater advancements in Android technology and more. The Phantom Z mini has a display of 5.0 inch super AMOLED touchscreen, 8MP front-facing camera with LED Flash and 13MP rear camera with auto-focus and Dual LED flash.
The newest Phantom Z mini also features an Octa-core process, dual SIM support, secondary microphones for active noise cancellation. The Phantom Z mini is supposed to be a trimmed down version of the Phantom Z but currently appears to feature similar specs and design as the flagship earlier released in June, more details expected soon.
The phone is only 6.6mm thin and here it now starts to sound like an F6. May be a little hardware update on the F6 to make it the A7? I don’t know.
The phone will come with a 2420mAh battery.

Here are a few specs of the Tecno Phantom Z Mini:

KEY FEATURES:
Android4.4, KitKat Octa-core Processor 5.0" Super AMOLED Touchscreen 13MP AF Back Camera with Flash 8.0MP Front Camera 16GB ROM+2GB RAM Normal SIM + Micro SIM 6.6mm Slim Body
DisplaySize : 5.0"
Material : Super AMOLED
Resolution 720*1280

POWER:
Battery Capacity : 2420mAh
StorageBuilt-in Storage: 16GB Storage
Memory Card Support

CAMERA:
Front Camera : 8.0MP with Flash
Back Camera : 13MP with Flash
Flash Light : Yes( Dual Flash
Front/Back)

CONNECTIVITY:
GPS Navigation : Yes
WIFI（WLAN) : Yes
Bluetooth : Yes
USB port : Micro 5pin
Earphone : 3.5mm
OTG : Yes

PRICE: Not Yet available

Will update when its released.

These are the only differences between the Tecno phantom Z and its mini counterpart.
1. Tecno phantom Z has 5.2 inch screen with Super amoled display
while Z mini has 5.0 inch Super amoled display
2. the resolution of Tecno phantom Z is 1920*1080 i.e full HD while Z mini has 1280*720
3 The battery in Tecno phantom Z is 3030mah while Z mini has 2450Mah
4. The onboard memory of Tecno phantom Z is 32GB while mini has 16GB
5. Camera in Tecno phantom Z is 16mp rear while the rear camera of Z mini is 13mp
6 . Tecno phantom Z screen is protected by second generation gorilla glass while Z mini is not
7. Finally from my observation, Tecno phantom Z mini design is classy and awesome