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 find suited most is putting a clickable caption below (maybe the title of the image). (The other suggestions are suitable for buttons rather than images, or just feel distracting to me.) That's my solution right now, but I wonder if there are any other creative ways for this?