Similarity in signal plots but dissimilarity in sensed content
First, the original $x$ and reconstructed  $\hat{x}$ signals have a peak amplitude around $0.35$. Their difference peaks above $0.40$. That happens between two time-shifted like-alike signals.

Second, the difference seems to relate to the amplitude. Processing maybe be non-linear, and it could be interesting to look at relative differences like $2(x -\hat{x})/(x +\hat{x})$ as well. 

To enhance understanding, what would  3D plots $(x[n],x[m],x[n]-x[m])$ and $(x[n],x[m],2\frac{x[n]-x[m]}{x[n]+x[m]})$ like like?