No tricks of Photoshop here. A just by chance combination of depth of field and the angle the butterfly is positioned, and perhaps its dark colouration, gives a three-dimensional impression to this image. I think it does, anyhow. Can anybody else see this, or it just me?
Photograph of Peacock (Inachis io) butterfly, taken August 2007, rear garden, Staffordshire. © Pete Hillman 2007. Camera used Sony Cyber-shot DSC-W1.