With floor-to-ceiling glass, the place has everything an achingly trendy hotshop (no titters) can offer. Even a spot of adult fun ...
This unexpected bonus was discovered by the Grey crew putting the final touches to a big pitch presentation late one Sunday evening.
Stopping for a breather on a darkened fifth-floor balcony, the team could only watch in compulsive amazement at the, er, free show put on under full light by the couple in the flat opposite.
The verdict: Could have been a bit more adventurous, but an athletic and varied exhibition.
Even when somebody hit the agency light switches, thus exposing the voyeurs, the performers seemed not to notice or not to care.
And what had been focusing the agency's mind? The contest for Toshiba's £25 million pan-Euro consumer electronics account.
"Nice if you could pull that off," a guest at last week's office opening told Chris Hirst, Grey's managing director. "I remember her in the flat opposite saying much the same thing," he replied.