Uploading photos to Twitter

If you are posting links to, say, your blog, is there any need to manually upload a photo nowadays? Or does Twitter always pull in the associated photo on both desktop and mobile?

There are WP plugins which do that for you or you can just make a recipe with IFTTT, where your WP post is the trigger and the image tweet is the action.

Edit: Rereading your OP, maybe i misunderstood it. Are you asking that if you post a link on Twitter whether Twitter will pull an associated pic with it or not? Because if that's what you're asking, then no, Twitter won't automatically pull any pics.