Some of the windows in 4510 have window coverings called "top-down-bottom-up".  They enable the shade to be lowered from the top for when you want both light and privacy, or raised from the bottom like ordinary window shades.

They are expensive and delicate so please operate them gently.  Here's how.

The string pull on the right-hand side of each shade controls the bottom-up function and is the one that is used most often.  Pull it to release the shade so it lowers by gravity, then pull to the right to lock the shade into the position you want.  Looping the string on the cleat is not required.

With the shade lowered, the string pull on the left can be operated in similar manner to lower the top of the shade for when you want to admit sunlight without visibility by neighbors.  In practice, I have rarely used this feature and thus leave the left-hand strings looped on their cleats.