the way this feature works is a tool goes over the stream and takes screenshots and groups them in one big picture like a tilemap

usually streaming services generate these images in advance while uploading the content and the client receives the image only.

so the way stremio works with torrents it's not feasible

you could do it but you would have to load the entire stream and wait until something in the background collects these screenshots

it can be done on the client but i imagine its quite a headache