This key indicates that the stereoscopic photograph No. 18 is a view east along Nanking Road 南京东路 from the corner of Honan (Henan) Road 河南中路. However, as wise 随意-sy pointed out, one of the hanging signboards is the Vong Ziang Silvermaker Store 凤祥银楼 (now known as Lao Feng Xiang 老凤祥), which has always been a little to the west, between Shanse (Shanxi) and Shantung Roads. So it is likely James Ricalton has confused one block with another and was actually standing at the corner of Shantung (Shandong) Road, looking east:
View east along Nanking Road, at the intersection of Henan Road:
The description of the image from the accompanying catalogue (1902) is in the kind of language that would not fly nowadays:
Ricalton's pictures were reproduced in multiple editions of postcard sets and photographic albums about Shanghai – here I wrote more about them.
The images No. 19 and 20 are also misplaced. The 锦成楼 teahouse was on Nanking Road between Fokien (Fujian) and Shanse (Shanxi) Roads: