Final answer:
Income received from a non-customer source increases assets on a company's balance sheet, as it represents an inflow of funds. This increase is reflected in the financial account of the flow of funds diagram.
Step-by-step explanation:
When income is received from a non-customer source, it increases assets on the balance sheet. This is because any income received, whether it be from a customer or a non-customer (such as investment income), represents an inflow of funds which adds to the company's assets. It does not directly increase liabilities, nor does it decrease other assets unless the income is specifically being used to offset or pay off an existing asset. The flow of funds diagram will reflect this increase in assets in the financial account, whereas the implications for the current account would be represented by the receipt of investment income or similar financial flows.