Light and Shadow Model with trick question

http://weelookang.blogspot.sg/2013/08/light-and-shadow-model.html

Light and Shadow Model with trick question.

Light and Shadow Model with trick question.
1 light source through a slit ( or 2 pink blocks) , notice the shadow-umbra and the light-bright light.
http://weelookang.blogspot.sg/2013/08/refraction-model.html
Ejs Open Source Light and Shadow Model java applet
author andrew duffy, remixed by lookang
from here http://www.compadre.org/osp/items/detail.cfm?ID=9983
https://dl.dropboxusercontent.com/u/44365627/lookangEJSS/export/ejs_model_light_and_shadowwee01.jar
https://dl.dropboxusercontent.com/u/44365627/lookangEJSworkspace/export/ejs_model_light_and_shadowwee01.jar

Thanks to msahinbulbul@gmail.com for his request!

I want to ask whether you can produce special version of light and shadow model?
As you know the original one presents a shadow in junction area, this is true. However, I want a new simulation which presents that area in light. I wonder how they explain the event according to this loaded/tricky simulations. We don't share this one because it includes wrong, unscientific presentations.

trick question 

i guess it can be shared as a conceptual trick question right?