interaction design – How to communicate that an image is clickable without explicitly telling that it’s clickable?

Say I have an image that is meant to contemplate, not to attract click. However, if someone is interested in it, they can click on it to explore more. I feel that having an explicit text saying it’s clickable will ruin the mood of the image. Is there a way to tell the user it’s clickable without having to explicitly telling that?

At first I think putting the direction in the tooltip of the image is a way, like how xkcd do with their comics. However this isn’t suitable for mobile. I also found this question Android app: informing users that an image is clickable, and the suggestion I fine suited most is putting a clickable caption below (maybe the title of the image). That’s my solution right now, but I wonder if there are any other creative ways for this?