A weezurd casts silent image to create an illusion of a building around her. A ranger interacts with the illusion by shooting it and beats the DC to realize it is an illusion. Does the ranger now see through the illusion or does the ranger only know it is an illusion (the weezurd still getting cover from the ranger)?
Silent image is a figment, so once the illusion is succesfully disbelieved you can see through it, however it retains a translucent outline.
-Nearyn
There is never any cover provided by the Silent Image. It could possibly provide concealment.
Once a figment is successfully disbelieved, only the outline is seen so any benefit would be gone at that point.
Yarp! What they said.