'roots' as a variation on the same general idea, consider another work, 'roots', which also depicts a cityscape cliffside... but note - the angle of perception has shifted from looking down to looking up... looking down is an appropriate way of 'cornering' something, to help contain or hold something... looking up, on the other hand, is a personification of how plants grow, from the roots upwards to the sky... roots also grow from the ground, or clinging to the side of something, like a trunk or a stump, establishing a firm foundation...