Space; Element of Design
Image source: https://www.nicholasgooddenphotography.co.uk/london-blog/negative-space-in-photography
Additional resources:
https://digital-photography-school.com/negative-space-in-photography/
https://photographyhero.com/using-the-rule-of-space-in-photography/
https://archi-monarch.com/principles-of-design/