My only suggestion is to reduce the image size. It is currently 500 x 500 pixels. PNG files can vary in size, depending on the image processing applied to them by various software. When I look at this image, it is only 12 kB in compressed form. But your machine may handle it differently and produce different results. At any rate, 500 pixels square is larger than you need for anything in Manager. Try exporting it with an image editor so you get something more like 200 x 200 pixels and see what happens.