If you take a picture of the standing wave at some instant, you would see something similar to the image shown below.
The particles between the first and the second node are moving downwards (or upwards). The particles between the second and the third node are moving upwards (or downwards). The particles of the two sections are off by a phase difference of $\pi$.
Adjacent loops are always out of phase by $\pi$ and only $\pi$.
If your question was which term to use, i.e: 'leading' or 'lagging',
you can use any term as they are mathematically equivalent because the phase difference is $\pi$.