try this....
instal astro file mgr, open it...open pictures,then there is a view button below,select directory options ,select show hidden files...apply..after that u can see a thumbnails folder ..open it..there will be the pictures..keep pressing on that pic,will show a option copy..then select it..and select home there,whole folders wil be displayed. open Bstfolder and then select Bstsharedfolder,before opening keep pressing,will see a paste option..select it...
then close it. goto C:\ProgramData\BlueStacks\UserData\SharedFolder...there is ur file..try it.