http://wccftech.com/galaxy-s9-rear-side-design-overhaul/

The ‘Infinity Display’ of the Galaxy S8 ( Amazon, $637.98) was one of the primary contributors to its success, so there is no reason for Samsung to change up the front of Galaxy S9 other than to increase the screen-to-body ratio. According to the latest rumors, the company is seeking to improve the backside of the flagship, so expect a design overhaul from the upcoming Galaxy S9 and Galaxy S9+, but with a twist from the back.

A leakster on Twitter believes that the Galaxy S9 could have a different back panel. According to a previously covered rumor, it is possible that the smartphone is accompanied by a various number of detachable modules with which it will be able to improve a particular aspect of its overall package. These modules could behave very similarly to Moto Mods, giving the Galaxy S9 more depth when it comes to overall functionality.