This mechanism is not quite correct; the product is not protonated until the addition of acid. The product is more acidic than the starting material, so the regenerated alkoxide would deprotonate the product in preference to the starting material. The deprotonation is mechanistically important as it drives the reaction thermodynamically.
Talk pages are where people discuss how to make content on Wikipedia the best that it can be. You can use this page to start a discussion with others about how to improve the "File:Claisen mechanism.png" page.