Final answer:
The e-commerce model of the online store Mary purchased her digital camera from is Business to Consumer (B2C).
Step-by-step explanation:
The e-commerce model of the online store from which Mary purchased her digital camera for her upcoming road trip is Business to Consumer (B2C).
In a B2C e-commerce model, businesses sell products or services directly to individual consumers. In this case, Mary, as an individual consumer, purchased the digital camera from the online store.
This differs from other e-commerce models like Business to Business (B2B), where businesses sell to other businesses, and Consumer to Consumer (C2C), where individual consumers sell to each other.