Creating a new business unit for the new brand can be used to have different styles and identities for the emails and landing pages. A business unit is a logical grouping of Marketing Cloud features, settings, users, and data that allows for brand separation within an account. A business unit can have its own sender profile, delivery profile, content, domains, and SAP. Reference: https://help.salesforce.com/s/articleView?id=sf.mc_co_business_units.htm&type=5

To automate a weekly SMS message to contacts who have a birthday that week, the Refresh Mobile Filtered List activity can be used to update the filtered list based on the birth date criteria. The Outbound Send activity can then be used to send the SMS message to the contacts in the filtered list. Reference: https://help.salesforce.com/s/articleView?id=sf.mc_moc_refresh_mobile_filtered_list.htm&type=5 https://help.salesforce.com/s/articleView?id=sf.mc_moc_outbound_send.htm&type=5

To limit subscriber records by BU based on the 'Region' profile attribute, Northern Trail Outfitters should select 'Define Subscriber Filter' for each BU on the BU Setup page and configure a condition to match the corresponding profile attribute. This will allow users who are assigned to a BU to only view and send to subscribers who have the same region value as their BU. Reference: https://help.salesforce.com/s/articleView?id=sf.mc_co_business_unit_setup.htm&type=5

To enable data extensions for sending SMS messages from MobileConnect, Northern Trail Outfitters should add two fields to their data extensions: a field of Locale type containing the country code and a field of Phone type containing the mobile number. These fields are required for MobileConnect to identify and send messages to mobile subscribers. Reference: https://help.salesforce.com/s/articleView?id=sf.mc_moc_create_a_data_extension_for_mobileconnect.htm&type=5

The Shipment object requires a Lookup to Lead or Contact1. This is because triggered sends can only be sent to Salesforce contacts, leads, or person accounts when object records are created or updated1.
An Apex Trigger is created on the Shipment object2. This is because a trigger is Apex code that executes before or after certain operations on an object2, and it can be used to invoke the Marketing Cloud integration action that triggers the email send3.