When the blinds are turned up the rounded side faces outward.
Turn blinds up or down for privacy.
With the slightly rounded side facing out and the concave side facing in you have better light control in the room with the blinds up than if you were to turn the blinds to face down.
Tilt them down and the blinds look softer and arguably better.
This may be a good strategy for the winter when you want to warm the room.
It gives you better privacy.
For heat control for summer.
With the blinds facing up the inside appearance may not be as appealing as when they re down but you reap greater privacy benefits.
Blinds turned down it may make it easier for peeps to peep in.
However having the rounded side facing out may not be as aesthetically pleasing as when the rounded side of the slats faces in.
Blinds turned in this direction offer more privacy and light control since the convex side faces the window blocking light or views from the outside.