the notes are inside the script itself. you should have seen them when putting it in the panel. although the images are larger, they are actually resized to 32x32 by this first line of code. you can edit that if you want it smaller.
//function takes 3 values: x, y, size. see on_size function if you want to update these relative to panel width/height
var ps = new playcount_sync(3, 0, 32);
//if you want to change the images, uncomment these lines below and modify the paths accordingly
//do not use fb.FoobarPath here as fb.ProfilePath already points to the same location if using portable mode
//ps.cross_img = gdi.Image(fb.ProfilePath + "my_theme\\images\\cross.png");
//ps.loved_img = gdi.Image(fb.ProfilePath + "my_theme\\images\\loved.png");
//ps.unloved_img = gdi.Image(fb.ProfilePath + "my_theme\\images\\unloved.png");
also, the background color is different
just like the old script, it uses your UI settings by default - but you can over ride this by using the right click menu>Background.