Identifying Flashback in Literature

In the context of storytelling, a flashback is a narrative device that transports the reader back to a previous event that is crucial to understanding the characters or plot. Authors often utilize this technique to provide depth to the narrative by revealing past experiences that shape the current actions of characters. Consider the following passage from a fictional story:

"As she gazed at the old family photograph, a wave of memories washed over her. She remembered the summer of 1995, when they had all gathered at the lake, laughing and splashing in the water, blissfully unaware of the hardships that lay ahead."

What type of literary device is primarily demonstrated in this passage?