english: One possibility is that the tomato particles near the walls of the container slowly get bumped towards the middle, leaving the soup they were dissolved in, which remember is basically water, near the edges.
non_english: Jedna od mogućnosti je da se čestice paradajza blizu zidova posude polako pomeraju ka sredini, ostavljajući supu u kojoj su rastvoreni, a koja je u osnovi voda, blizu ivica.