The way food is cut can alter the way a person perceives its flavor due to a combination of scientific and psychological factors.

The way food is cut or shaped can influence its perceived flavor, according to a recent NPR article. 
Writer Carolyn Beans acknowledges that there doesn’t seem to be a precise reason why this happens, but several experts provide some possible explanations. 
Leslie Brenner, restaurant critic for The Dallas Morning News, talks about the importance of surface area while cooking.
She notes, "The cooking method is going to penetrate...finely cut vegetables more. You're going to get more of a reaction."
Meanwhile, Brendan Walsh with the Culinary Institute of America explains that rounded vegetables give a feeling of being more succulent while square foods are often considered more “rugged or tough.” 
Cutting produce in general has been shown to trigger internal changes which often lead to faster deterioration, especially as “pieces get smaller.” 
However, breaking down the cells also causes a reaction which makes tomatoes more aromatic, and onion and garlic more flavorful. 
In addition to how ingredients are handled, industry experts have long found that numerous factors like color, sound, even the type of cutlery used can alter the flavor of food psychologically.