Try uploading it again its very blurry.
two techniques come to mind. first, it could be fondant appliques that are applied to the cake and then pearlized. I tend to think that's what it is.
Second, it could indeed be stencil if the stencil is applied thick enough. I often put a thicker layer of the stenciling medium and then lift off the stencil leaving bas relief effect.
The picture is blurry, but it could be brush embroidery?
I think I recognize it. It from a mold made by Wilton. Fondanmt/gumpaste the applied to the cake.
OTOH, is near too blury to tell what it is . . .
Picture is blurry, but my guess is brushed embroidery......