This is the A320neo SHARP (SHort AiRfield Package) that Airbus designed at the Filton, UK Plant in conjunction with their engineering colleagues in Bremen, Germany.
It's a package of aerodynamic improvements meant to increase wing lift at low speeds. The original impetus to develop the enhanced takeoff and landing performance for short fields was a desire to operate the A320neo into Rio de Janeiro's Santos Dumont airport, whose runway is only 1,300m (4,265'). In addition to the short runway, there is a mountain to one side and a long bridge on the other to add to the landing challenge.

It would take dozens of pages to describe how each component improves airflow and enhances low speed lift and performance. But the key component of the package is a Kevlar composite panel modification to the wing's Root Fillet Fairing to optimize airflow at the wing root. This minimizes interference drag by easing the airflow transition between airframe components and retards the onset of stall at low speeds. This enables greater lift at lower speeds, both keys to improved short field capability.
Modern airliners have adopted any number of aerodynamic enhancements. Perhaps the most famous of which are the widely adopted winglets. The blended neo winglets have a relative drag reduction at cruise of about 4%. The difference with the SMART package is that the aerodynamic enhancements target low speed airflow management with the goal of increasing low speed lift.
AIRBUS PREPARES “SHORT AIRFIELD PACKAGE” MODIFICATION FOR A320NEO
Airbus Readies Short-field Mod for A320neo
Airbus designs short airfield package
DEFINITION AND DISCUSSION OF THE INTRINSIC EFFICIENCY OF
WINGLETS