$image_file_full = <full path to image>
# get a cell in which the image is to be stored
$cell_tg = $sheet->Range($range);
# insert the image
$pic_cur = $sheet->Pictures->Insert($image_file_full);
# position the image in the top left hand corner of the cell
$pic_cur ->{Top}  = $cell_tg->Top;
$pic_cur ->{Left} = $cell_tg->Left;