Take a look at this commercial from 2010 for the Sony Ericsson Xperia X10 mini. Sure, it's a cute ad, but take a look at how thick the device is. If you're curious, the measurement of the phone was 16mm thick. As you would imagine, the rest of the specs seem like they are a century old. Remember that the full-size Sony Ericsson Xperia X10 had a 4 inch screen, which is even smaller than today's "mini" smartphones. The Xperia X10 mini carried a 2.5 inch screen with resolution of 240 x 320. Under the hood was a single-core 600MHz Snapdragon S1 CPU with the Adreno 200 GPU handling graphics. A 5MP camera was on back and there was a 16GB microSD slot available.
We've come a long way in just four short years, especially Sony. The Sony Xperia Z1 Compact is now considered the gold standard of "mini" phones with flagship-type specs. That model features a 4.3 inch screen with resolution of 720 x 1280 and is powered by a quad-core Snapdragon 800 CPU. A 20.7MP snapper adorns the back with a 2MP camera on the front.
You can check out the extremely thick Sony Ericsson Xperia X10 mini, starring in a rather cool commercial, by clicking on the videos below.
source: SonyEricsson (1), (2)