It looks like the yellow one going to the 3-terminal Wago is the common and is supplying always-hot (yellow).  This comes from supply (in either left or right conduit) to a downstream outlet (down the other).  

The other two yellows going into 2-terminal Wagos are travelers.  They seem to go into the center conduit, along with a neutral, which is the return for the light, and two unrelated oranges. 

Someone might send a memo to this electrician reminding him all those different colors of THHN wire are on his truck for a reason.  Using the same color for always-hot and travelers is kinda confusing.