We have already the possibility of intervening automated algorithms and adding custom screenshots, so if we allow theme authors to claim their themes they can add those close-ups themselves, which would be an obvious next step.

However, today this is technically challenging problem since the screenshots are not made manually, but with supervised algorithms. I dream about a day that we can pinpoint visually which area of the image are visually interesting/aesthetic to make a close-up, utilizing Neural Networks better. We need Deepmind for themes, the way google has it for their Photos.