At the top of the Tokyo Sesame Place escalator you would be at the Big Bird head. You could continue through Big Bird's mouth up to Barkley's Walkway (a narrow observation deck) or you could stay at Sesame Square which would give you access to the rest of the attractions.
Sesame Square had the round sign similar to the signs Milton Glaser designed for Sesame Place in Langhorne, PA.
Below is an image created from stills from a video sweep of the area.
Many pictures make it look like the Big Bird head was directly in front of the escalator, but it was a dozen or so feet back, as you can see in this picture: