А я в result_modifier.php обычно пишу что-то вроде:
<?
foreach($arResult["ITEMS"] as $key=>$arElement) {
foreach($arResult["ITEMS"][$key]["PROPERTIES"]["PHOTOS"]["VALUE"] as $keyCodeImage=>$idImage) {
$arImageSmall = CFile::ResizeImageGet($idImage, Array("width"=>130, "height"=>130), BX_RESIZE_IMAGE_PROPORTIONAL_ALT, true);
$arImageLarge = CFile::ResizeImageGet($idImage, Array("width"=>1400, "height"=>1400), BX_RESIZE_IMAGE_PROPORTIONAL_ALT, true);
$arResult["ITEMS"][$key]["PROPERTIES"]["PHOTOS"]["PROCESS"][] = Array (
"PICTURE_SMALL_WIDTH" => $arImageSmall['width'],
"PICTURE_SMALL_HEIGHT" => $arImageSmall['height'],
"PICTURE_SMALL_URL" => $arImageSmall['src'],
"PICTURE_LARGE_WIDTH" => $arImageLarge['width'],
"PICTURE_LARGE_HEIGHT" => $arImageLarge['height'],
"PICTURE_LARGE_URL" => $arImageLarge['src']
);
}
}
?>