How to access secured S3 objects without presigned URL or cognito token?

Look at the social media sites, we can access there content(videos/images) without signup/signin. So we can't use cognito tokens as a authorization to access s3 objects, as we want our user can access content(videos/images) without signup/signin.

So many people suggested that I should use presigned URL but one expert said: Typically we recommend to generate the presigned URLs only when you want to download the object.

Then how to acess the objects according to my need :

1. user can see the post of image/video with the post link without signin/signup.
2. I want to make my bucket private
3. Cloudfront with s3 orign is good but that is not secure as we are not going use cognito token.
4. My overall need is user with my site/app can access objects without signin/signup

Is there any way to create app token that will expire within 7 days ?