Why do Redgifs links don't fit for 'image' posts like Gfycat's ones?

So the question is in the title, why this doesn’t it work?
Redgifs is the same as Gfycats but just intended for adult but its links don’t work for image posts as Gfycat’s ones. I’m an adult creator and I have to make link posts instead of the image ones like I did before. :((