Well to me it is all about what kind of calories we are talking about.
I mean you could be eating 1200 calories a day by having one big mac meal/ day only or 1200 calories of veggies whole grains and good fats.
It is normal to hit a plateau once in awhile and some people has plateau that are longer than others. The important thing is to keep doing what you are doing if you went the healthy way of course. If you are eating bad calories, remove them, go with whole food. It will make a difference.
Personnally my diet is between 1200-1400 of only good calories and I am doing pretty well.
Maybe look at what you are eating? question yourself on these days you eat 1500 if some of these calories are really necessary (like some fats or proteins.. maybe you have too many of them?)
Depending the diet you are following, just make sure the calories you do take are good ones that will sustain you and not starve your body
You look great in that picture and look at all the weight you already lost! come on keep going!! You can do it