Most likely, the Grand Theater referred to by the photographers was the Grand Opera House, which was located at 217 Cherry Street.

Sample of advertisements in image: Cody Detective Agency and Merchants Patrol Service. After the Show Let Us Go to Tien Sien Lo - Finest Chinese Restaurant and Chop Suey House on the Coast. You Are Only One of a Million People in the Northwest Who Read Our Theatre Curtain Ads. Try a New York Box Lunch Delivered at Your Place of Business. Going to Vancouver B.C? - Hotel Winters, A Perfect Hotel for Particular People. Dancing Guaranteed in 4 Private Lessons - Prof. Stevens. A Needle Spray Bath in Your Home Gives Health - Beauty - Vigor and Costs Only $25.00. D.S. Johnston Co. - Pianos, Organs, Pianolas, Talking Machines.
Handwritten on sleeve: Grand Theater [Ext. +] Curtain.
Webster & Stevens number: 4392