Objective ways to print images in 5.7

First, get page's image attribute value like:

$img = $page->getAttribute('example_image_attribute_handle');
if ($img) {
    // do something
}

Case 1: Print responsive image (if your theme supports responsive image)

$tag = Core::make('html/image', array($img))->getTag();
echo $tag;

Case 2: Add some attributes to the image

$tag = Core::make('html/image', array($img))->getTag();
$tag->alt('alt test');
$tag->title('title test');
$tag->addClass('example class');
echo $tag;

Case 3: Remove some attributes from the image

$tag = Core::make('html/image', array($img))->getTag();
$tag->width = null;
$tag->height = null;
echo $tag;

Case 4: Do not use responsive image (picture element)

$tag = Core::make('html/image', array($img, false))->getTag();
echo $tag;

Case 5: Get thumbnail src of the image

$src = $img->getThumbnailURL('small');
echo \HtmlObject\Image::create($src)->alt('small size image');

Note: Loader::helper('image') is officially deprecated.