This is a recent tree climbing discovery the ability to climb drooping limbs almost like ropes. In addition to having to negotiate extra branches, the arch away from the origin and the curves in he branch add extra elements of sway, roll and flex that make it far more complex then a rope climb.
Its difficult to make it fast or smooth but a very rich movement environment none the less.
If you tree this be very cautious as you introduce your weight to the tree limb I am myself just discovering what the limits are for this type of movement.
This beautiful tree is either a Sycamore or london planetree.