Sentence:  The half-dozen pieces […] were painted white and carved with festoons of flowers, birds and cupids. [...]  The bed was the most extravagant piece.  Its graceful cane halftester rose high towards the cornice and was so festooned in carved white wood that the effect was positively insecure, as if the great couch were <WSD>trimmed</WSD> with icing sugar. 
Meaning of the word marked with <WSD> tags:  To decorate or adorn; especially of a Christmas tree.