If you have run an import of a QFX/OFX/CSV file from the bank or have processed a Direct Connect/Moneyspire Connect import, you will see gray and white down-arrow icons in front of the accounts (both, accounts side-menu and the main Accounts section). They mark the accounts new data has imported into.
If you open such an account, all the imported transactions would also be marked with this icon:
These arrows are not permanent!
They only show the transactions that were imported during the current session. If you close the application and re-open it again, the arrow icons would be gone.