To create a drawing, you have four sources : File, GD, Base64 and ZipFile.
To create a drawing, use createDrawingShape method of slide.
$oShape = $oSlide->createDrawingShape();
$oShape->setName('Unique name')
->setDescription('Description of the drawing')
->setPath('/path/to/drawing.filename');
It's an alias for :
use PhpOffice\PhpPresentation\Shape\Drawing\File;
$oShape = new File();
$oShape->setName('Unique name')
->setDescription('Description of the drawing')
->setPath('/path/to/drawing.filename');
$oSlide->addShape($oShape);
use PhpOffice\PhpPresentation\Shape\Drawing\Gd;
$gdImage = @imagecreatetruecolor($width, $height);
$oShape = new Gd();
$oShape->setName('Sample image')
->setDescription('Sample image')
->setImageResource($gdImage)
->setRenderingFunction(Drawing\Gd::RENDERING_JPEG)
->setMimeType(Drawing\Gd::MIMETYPE_DEFAULT);
$oSlide->addShape($oShape);
use PhpOffice\PhpPresentation\Shape\Drawing\Base64;
$oShape = new Base64();
$oShape->setName('Sample image')
->setDescription('Sample image')
->setImageResource($gdImage)
->setData('data:image/jpeg;base64,..........');
$oSlide->addShape($oShape);
use PhpOffice\PhpPresentation\Shape\Drawing\ZipFile;
$oShape = new ZipFile();
$oShape->setName('Sample image')
->setDescription('Sample image')
->setPath('zip://myzipfile.zip#path/in/zip/img.ext')
$oSlide->addShape($oShape);