macwest - When you try to post a cool image, but the internet decides

When you try to post a cool image, but the internet decides to replace it with something stupid or make it disappear. It’s like the image got exiled.

I posted my dog’s dance, and it turned into a grumpy face. Why would you do that?

My hotlink got blocked. Now my image is just a man yelling. That’s not even fair.

I tried to show my cat doing tricks, and it just vanished. What’s happening?