I disagree. The longer term LOD variation was removed in in the inset, thus reducing the fluctuation extremes from 2 to 1.
This is the paper by Chao cited in the figure:
http://ivs.nict.go.jp/mirror/publications/gm2004/chao/
Here is another from Chao, showing the wavelet decompostion of LOD signal

B. F. Chao, W. Chung, Z. Shih, and Y. Hsieh, “Earth’s rotation variations: a wavelet analysis,” Terra Nova, vol. 26, no. 4, pp. 260–264, 2014.