get_stylesheet_directory was necessary for the glob function to work, you need a combination of both, e.g. fetch the files in that directory:

$imagePath = get_stylesheet_directory() . "/IMAGES/sponsors/";
$filesList = glob( $imagePath . '*.{JPG,jpg,PNG,png}', GLOB_BRACE );

and display the files at that URL:

$imagePathURL = get_stylesheet_directory_uri() . "/IMAGES/sponsors/";
...
    echo '<img src="' . esc_url( $imagePathURL . $file ) . '">';

Notice that I wrapped it in esc_url, this is escaping and we do it to keep things secure and avoid injection attacks.

TLDR:

• glob wants a folder path
• but <img wants a URL instead

get_stylesheet_directory was necessary for the glob function to work, you need a combination of both, e.g. fetch the files in that directory:

$imagePath = get_stylesheet_directory() . "/IMAGES/sponsors/";
$filesList = glob( $imagePath . '*.{JPG,jpg,PNG,png}', GLOB_BRACE );

and display the files at that URL:

$imagePathURL = get_stylesheet_directory_uri() . "/IMAGES/sponsors/";
...
    echo '<img src="' . esc_url( $imagePathURL . basename( $file ) ) . '">';

Notice that I wrapped it in esc_url, this is escaping and we do it to keep things secure and avoid injection attacks.

TLDR:

• glob wants a folder path
• but <img wants a URL instead