Simple drawing a good predictor

Is this bag lying down or standing up? Or can you see it both ways?

Some days I can flip the bag drawn by one of my doctors. Some days I can only see inside the bag one way.

The one-way day is not a good day for me to go looking for Waldo, finding the "magic picture" hidden in scribbles or picturing what the completed quilt or necklace will look like.