。
When she saw that photo, the memories came flooding back.
Literal
She [topic-は] that photo [object-を] saw [when-と] memories [subject-が] revived-came.
~と here is the conditional/temporal と meaning 'when, as soon as,' typically used for inevitable or routine consequences — distinct from quotative と and conditional ~たら/~ば. 記憶がよみがえる (蘇る, 'memories revive / come back') is a stock phrase for sudden recall, particularly the rush of forgotten or buried memories triggered by a sensory cue. The trailing ~てくる adds direction toward the speaker — the memories come gradually, washing into awareness rather than appearing all at once. Photographs are a classic memory trigger in Japanese literature, often serving as the gateway to 回想 ('flashbacks, recollections').