Once thought to be broken neon by many, the sign appears to be hundreds of red light bulbs, indicating that the sign was likely added before Father Divine took ownership of the property, predating the use of neon.
The age of the sign adds a new layer to the building's history. Prior to the use of neon, incandescent light bulbs were commonly packed closely together and used to illuminate similar signage. Many historic examples still exist in places like Las Vegas, but most were replaced with neon or fluorescent tubes that were cheaper and better traced the curves of the signs. Many more were removed all together, particularly today with durable and even cheaper LED illumination.
It will be interesting to see how Eric Blumenfeld plans on restoring the sign, whether it will continue to be standard, red light bulbs, or if it will be replaced by neon or LED.
*as someone pointed out, I boneheadedly missed the obvious. The Divine Lorraine Hotel sign was obviously installed after Father Divine purchased the property, considering it was formerly named the Lorraine Hotel.