This photo has a shallow depth of field. I think the photographer used a maderate aperature such as 5.6 because you can still kinda see some other flowers in the bakcground. 

I think the Photographer used a larger depth of field because the photograph has a short depth of field, and only the flowers are in focus.

I think the photgrapher used a moderate aperature such as 5.6 because the depth of field is shallow, but it is not very shallow.