Problem loading images inside a drupal table

Hi all,
I need to show images for each row inside a drupal table. These images are Base64 coded and I'm trying to use the following code

$content = "data:image/jpeg;base64, ".$image_flow;

$form['table']['row'.$key] = [
			'imgList' => [
					'#type' => 'item',
					'#markup' => '<img src="'.$content.'" alt="Icon software" class="img_details"> ',
			]
];	

The content "data:" disappears when the form has been built, so the images are not displayed.
No issues found using twig way.

Do you have any suggestions?

Kr,
Luigi