The process shown happens during prophase I of Meiosis l. We begin with two replicated homologous chromosomes on the left. These move close together and we have synapsis. At that point, there is a possibility for "cross-over" and sequence exchange between sister/non-sister chromatids. Ultimately, the result will be four gametes, each with one of these chromosomes, and at least two of these would be non-identical to the parent. In practice, as many crossover events could occur for each chromosome, which really creates diversity in the gene pool.