That’s hot linking and is frowned upon to the point that some sites will block it. You might be seeing the cached version you post over here but everyone else gets a broken image.
Far better to use a hosting services. You could use Pixelfed but it could get a bit messy and it is designed as an Instagram replacement. You’ve be better off using a dedicated image host:
Lensdump.is my general image host that I use for all sorts of bits and bobs.
Catbox hosts images and videos - I use it for the latter.