Like many reef fish they change patterns quite dramatically - this is the interesting inbetween bit. You may have guessed its a predator and that jaw apparatus unfolds to reveal a) impressive suction potential for engulfing stuff and b) some decent dentistry. Note the bizarre extended dorsal fin rays at the front, I presume these are for display. The "spotfin" refers to the black blob on the second dorsal but far more interesting is the faint reticulate patterning on the face. They remind me a little of maori or polynesian tattoos.