![](https://openlab.citytech.cuny.edu/comd1340ol89fall2020/files/2020/12/Silouhette-768x1024.jpg)
Primarily focusing on the outside of the window and lowering the exposure is what helped create the contrast and darkness that helped create the silhouette in the first place, and bringing down the black just made it even darker which in turn makes the point the picture is trying to capture come across more successfully.
What makes the silhouette is the difference in light levels. You need to put your subject in the dark room against the light outside the window.