On an existing-item card the yellow Receipt Mismatch Found banner appears when the receipt disagrees with what is stored on the ingredient: a different pack size or unit of measure, a price change (shown as Price: $old → $new with a percentage, red for an increase and green for a decrease) or a different supplier (Supplier: old → new). When the unit differs, a Convert, Recalculate Macros, and Update Stock link converts the receipt quantity into the ingredient's existing unit (the message reads e.g. Converted: 5 lb → 2.27 kg), recalculates macros and updates stock accordingly. The banner is informational; nothing changes until you confirm the card.