Typically it is best practice to avoid using "explicit" Deny whenever possible because it will override all other permissions. Also, Manage Security is checked in that image, which would allow the user to change those settings anyway.

All you need to do is remove Allow on the modify and delete rights and it will yield the same results; this is an "implicit" deny.

If you want to allow those actions for children and not the parent, just split it into two rules with different scope.

Allow browse, etc., for "This Entry Only", then allow the other permissions (modify, delete, etc.) for "Subfolders and documents only"