[Solved]-Highcharts: Renderer positioning issue on different screen size breakpoints-Highcharts

You forgot to include chart.plotTop in the calculations. Properties plotX and plotY from points are in relation to plotArea and the chart.renderer method includes the entire chart.

this.renderer.image(
    url, 
    point.plotX - (imgWidth / 5), 
    point.plotY + this.plotTop - imgHeight, 
    imgWidth, 
    imgHeight
).attr({
    zIndex: 3
}).add();

Live demo: http://jsfiddle.net/BlackLabel/svp7rnkg/