Dimensions of the Nexus 7 (weighing 340g), sticks within a height of 198.5mm, a width of 120mm & a depth of 10.45mm. The 312g iPad Mini2 size is 200 mm in height, 134.7mm in width & a depth of 7.2mm
Display-wise, the Nexus 7 houses a 7” 1280×800 (216ppi) screen with HD IPS technology, while the iPad Mini2 has a 7.9‑inch (diagonal) LED-backlit Multi‑Touchdisplay with IPS technology 1024×768 resolution at 163 pixels per inch (ppi)
The Operating System on the Nexus 7 is the acclaimed Android version 4.2 (Jelly Bean), while the powerhouse of the iPad Mini2 is brand new iOS 7 (in India on 19th Sept.)
Storage: The Nexus 7 storage comes with a 1 GB RAM & a 16GB/32GB internal storage capacity, while the iPad Mini2 simply comes in denominations of 16GB/32GB/64GB
Camera: The Nexus 7 Camera is 1.2 MP front facing camera as compared to the iPad Mini2 camera which is rumored to have an impressive 8MP one.
Another comparison could be made to the processors used. The Nexus 7 functions on an NVIDIA® Tegra® 3 quad-core processor, while the iPad Mini2 runs on a Dual-Core A5 chip.