What does the following statement mean? Any geometric intuition would be very helpful.
L.C. Young constructed a closed curve $\gamma$ in the Euclidean space $\mathbb{R}^4$ such that the least area of a surface with boundary $2\gamma$ is strictly less than twice of that with boundary $\gamma$.
https://link.springer.com/content/pdf/10.1007/BF02851262.pdf
The following paper says this in the first page https://arxiv.org/abs/1412.0101
I have no formal math background. What does $2\gamma$ mean? Any help in understanding this would be good.