What do the different member icons indicate?

We create a Mailchimp Member record for every subscriber in Mailchimp. Those records in Salesforce can be related to a contact, lead or person account via a lookup relationship. 

Object icons

We use standard object icons to indicate the related record, in both the audience list and member components:

• Grey - The member isn't currently connected to any record ("Not linked to Salesforce")
• Fuchsia - The member is related to a contact. 
• Blue - The member is related to a lead.
• Purple - The member is related to a person account.

Icon transparency

On the membership component, we will also surface membership records where an email on the contact matches the email on a member, even if that member is not directly related via lookup in the underlying data. On surfaced records, the icon will be semi-transparent. 

NB: Field mappings are only applied between directly related contact and member, and for only mapped email field.