I played a bit more and it seems that if you open a post then close it the post remains in your scroll where you started. Pressing the eye seems to refresh the feed and remove the posts you have ‘viewed’. By ‘viewed’ I refer to opening a post or image that tells Memmy you have ‘read’ it as per the settings. The eye is just a refresh it would seem.

Thanks for the comments, it gave me some ideas to play with around this.

Hide read posts.

Only shows if hide read posts is selected in settings.

To devs, maybe there needs to be an explanation when you select this setting? This question is asked a lot.