Hi pkuadt,
I think the answer depends on how you’re running and hosting tiddlywiki.
If you use github, for example, there’s a plugin by @saqimtiaz that enables you to drag images to your wiki, but which does not then load down the wiki with the full image data, but instead creates corresponding files within your github directory. (My explanation may be clunky — see this thread: File Uploads plugin beta: feedback)
I’d love to see a plugin like that for tiddlyhost. For my uses, tiddlyhost is great except that I need a separate hosting solution for my images (apart from whatever tiny ones I don’t mind getting directly encoded in the wiki). I’m doing OK with dropbox, but doing so much copy-paste of image urls (and changing dl=0 to raw=1 manually, or setting up an automation to do that) is sometimes a hassle.
I think people who use node.js and/or Bob may have entirely different solutions. I know just enough to know that I don’t know enough 
— that is, enough to suggest that more information might enable others to help you better.