well, Gemini clients like Lagrange allow to show inline images when you click on an image link. Text based clients, like Amfora, usually allow to watch the image in another 'window'.

For example here: gemini://text.eapl.mx/en-making-a-tic-tac-toe-variant and there https://text.eapl.mx/en-making-a-tic-tac-toe-variant

I agree that some topics require images to make it easier to explain.