Neither, because the shoes could be made of velvet, in that case, then it is neither or if the shoes are not really made of velvet, it is a metaphor. it is definitely not a simile
        
                    
             
        
        
        
Example:
 In Abraham Lincoln's speech, he used various types of rhetorical devices, including pathos, biblical allusions, logos, and parallelism to convey hi to convey his message.
 
        
             
        
        
        
Answer:
She shames him.  She thinks the crime could be washed away.  She also thinks if they ignore the situation it will take care of itself; if they can wash away their sins....then their conscience would be cleared - or so she thinks...
Explanation:
She is a manipulator and she is controlling.  She can be violent and cold-blooded and will ridicule/shame him.  She calls him a coward because he had not put the daggers where they were supposed to go.  She goads him and even compares how he did not go through with the murder like he was supposed to, is also the type of husband he has become.