Shenzhen processing Center, has imported mutual seal (at home by the turn)

Can someone let me know what this means below?
Number: CJ164138804US
Package status: In transit
Destination: China
2018-08-06 14:23 Shenzhen processing Center, has imported mutual seal (at home by the turn)
2018-08-06 14:23 Transfer to Customs
2018-08-06 14:22 Shenzhen, imported open and demolition
2018-08-04 09:04 Shanghai Processing Center, has imported mutual seal (domestic warp)
2018-08-04 08:44 Shanghai, transfer of quality inspection
2018-08-04 08:44 Shanghai Processing Center, has imported mutual seal (domestic warp)
2018-08-04 08:43 Shanghai, the import has been opened and dismantled
2018-08-04 06:42 Shanghai, the import has been opened and dismantled
2018-07-31 15:17 Miami processing Center, has left

Hi.
I am tracking a parcel (RG639967238CN) and the last status I got was:

Sat, Nov 04, 2017 13:35
[Beijing processing center] has imported mutual seal (domestic by-turn)
Fri, Nov 10, 2017 10:27
[Nanning] has been imported open and demolition
Fri, Nov 10, 2017 17:04
[nanning processing center] has imported mutual seal (domestic transfer)

I haven't got another new status since that date and the logistic order was delivered on October, 24
What's the meaning of those "has imported mutual seal" ????

Thank you.