Final answer:
Amanda's data warehouse design may have difficulty incorporating external data due to its potential non-conformity with the warehouse's expected data schemas and formats.
Step-by-step explanation:
The data warehouse design that Amanda is working with might not be able to accommodate external data that does not conform to the pre-established schemas or formats expected by the data warehouse. This can include data that comes from outside sources such as third-party feeds or real-time streams which might not be structured in the way the data warehouse requires. If the design prevents any type of data, it is more likely to be this kind of data because of its variable structure and content.