This is a guide to activating the podium and finding the symbols in The House of Blossoms secret passage in Chapter 3 Dirty Secrets in Thief 2014.
Opening madam Xiao-Xiao’s strongbox: http://wp.me/p1SfP0-1Gn
All Thief guides: http://wp.me/P1SfP0-1FJ
Finding the Symbols
To activate the podium you need to find three symbols in The House of Blossoms Secret Passage. The first is in the area were the podium is on one of the walls:

A Symbol to Activating the Podium in The House of Blossoms Secret Passage in Chapter 3 Dirty Secrets in Thief 2014
The rest are in the rooms that you can peak into through the wall along the Secret Passage:

An Example of One of the Peep Holes through which the Other Symbols can be Found to Activate the Podium in The House of Blossoms Secret Passage in Chapter 3 Dirty Secrets in Thief 2014
Activating the Podium
To activate the podium move the rings of the medallion so that the glowing signs are at the top and insert the medallion into the podium.