Can the information received by the secondary card be seen by the primary card?

The main card can see the information.

There is a * * * account sharing relationship between the primary card and the secondary card. The primary card can view and manage the communication records and short messages of the secondary card.

This is because the main card and the auxiliary card use the same account, so the main card can view the short message content of the auxiliary card by logging in the account or using related mobile phone applications.