Sounds like you are specifically looking for a client focused on image browsing. In that case I would suggest linking to vger.app, phtn.app or blorp which I linked in another comment. Lemmy 1.0 will also have a card view which admins can set as default, where images are already expanded.

see another interesting post, image to small, can’t see so I have to click – lemmy.ml/post/42501566

This is only the link preview (indicated by the arrow icon), not an image post. Is the icon too small?