When I bought these violets, the leaves were pointing up. Now, they seem healthy and are even flowering, but the leaves are going downwards. What makes them point up or lay down like that?
They looked like these originally:
As Wayfaring Stranger has pointed out it happens as new leaves grow. If you look carefully at the crown, as your plants get older you may note that the shape changes from a little round bump to a vertically extended shape. Imagine a pencil being pushed up through the soil - at first the leaves grow out of the flat or rounded top of the eraser and stand up straight. Then as new growth happens at the eraser tip they push the old leaves to the outside; the "pencil" emerges further, the old leaves are no longer at the top where the eraser is, they are now growing out of the sides of the pencil, out of a vertical surface and therefore the petioles are horizontal.
The upright tube shape becomes clearer as the plant moves into old age and needs renewal.