As i undersfand it the special thing is not the phone itself, but who made its processor and how.
Most advanced chips are made by tsmc/samsung/intel with Western technology (especially by ASML).
This one is made by SMIC a partially state owned Chinese company with a lot of domestic technology used. Apparently they are using a 7nm DUV process, which is quite advanced. Although not as much as the current smaller nodes used by the other manufacturers, which use EUV (a newer significantly more complex technology that succeeded DUV).
The technology used in manufacturing advanced chips is one of the most complex things in the world. huawei and china are targets of sanctions limiting their access to western technology in this sector. So it is of particular interest how far they’ve come with their own domestic production. Another debate related to that is how much of that is based on stolen technology vs their own research.