Code doesn't really matter since the example in the readme does the same thing, but you can see it produces an extremely dark version, other than making it really dark it seems to have the rest of the quality intact..
(does this with all images)

 $image = ImageResize::createFromString(base64_decode($image_data_base64));
 $image->crop(200, 200)
 ->save($destination . $time . '_s.jpg', IMAGETYPE_JPEG)
 ->resizeToLongSide(1300)
 ->save($destination . $time . '_b.jpg', IMAGETYPE_JPEG);

1

not using chaining at all produces fine images.