To my EYE & SENSIBILITIES a good/great picture is one which, first and foremost, is visually interesting / engaging to view. If such a picture conveys a "meaning", personal or universal, for an individual viewer, so much the better. However, both qualities will be judged entirely by a viewer's subjective eye and sensibilities.
It is also my firm belief that the picture should do the "talking". While a simple Artist Statement is a never a bad idea, rambling statements composed of pyscho-self-analytical artspeak mumbo jumbo is never a good idea. iMo, they read like an instruction manual telling the reader what to think about when viewing the picture(s). Whereas, again iMo, I believe the best manner in which to approach the viewing of a picture is with a blank/open mind.
In other words, as the old railroad crossing signs suggested, when viewing a picture, the best approach is to STOP, LOOK, LISTEN.