Does anyone know how this void above Giant IMM came to be?

Before Giant got downsized in conjunction with the mall's renovation works lately, there's this giant void (pun intended) right above Giant. It stuck out like a sore thumb but has been mostly covered up lately. It clearly looked like it was meant to be an atrium area and if my memory served me well, there used to be escalators connecting the upper floors despite the hoardings. I did ask around my circles but no one seems to have a concrete answer. Does anyone know what this area used to be? Or was it an intended mall layout that didn't come to fruition?

Before Giant got downsized in conjunction with the mall's renovation works lately, there's this giant void (pun intended) right above Giant. It stuck out like a sore thumb but has been mostly covered up lately. It clearly looked like it was meant to be an atrium area and if my memory served me well, there used to be escalators connecting the upper floors despite the hoardings. I did ask around my circles but no one seems to have a concrete answer. Does anyone know what this area used to be? Or was it an intended mall layout that didn't come to fruition?