Yeah, that. But that photo is very drab.

Imagine several rows of those, each row a dozen cabinets or so long. Like this: https://commons.wikimedia.org/wiki/File:Lucent_5ESS_GSM_Mobi...

Especially when it's sharing space with a mishmash of other equipment, all gnarly looking: https://www.ven-tel.com/img/product/EWSD.png