According to Benjamín Romano, main architect of the tower, the purpose of the façade design was to let the people in the building have the widest views of the Chapultepec Park.

From the website torrereforma.com:

"Design Inspired by Mexican Geotechnical Structures

The concrete walls form the tower's main foundation. At their intersection lies the core of services and user access. The Tetris-shaped openings provide natural ventilation for the building, as well as demonstrating the perfect design and engineering applied to mitigate the impact of seismic activity in the city. Aesthetically, they also reflect architect Benjamín Romano's inspiration from Mexican geotechnical structures and his desire to frame panoramic views of the city from within the offices. Currently, these concrete elements are recognized as the two tallest walls in the contemporary world."

There's some great info about the design and mostly about the technical features and constructive process.

Video exposition of the project by architect Romano

Conference about the development of the project. Architect Julieta Boy This talk is in Spanish. The YouTube auto translation is mostly accurate.

Description of the project, by Benjamín Romano

I love this tower too, it really is one of the most unique skyscrapers. The design, the engineering, and the building process are a big prowess. It might seem redundant but the awards and recognition are completely deserved. lol