Recalling something related to A; 'speaking of which', 'by the way', 'now that you mention it'.
Long explanation:
The A。そういえば B。grammar point is used when something related to A is recalled or brought up. It can be translated as 'speaking of which', 'by the way', or 'now that you mention it' in English. It is commonly used to connect two related topics or ideas in a conversation and indicates a change of focus. The formation consists of two clauses: the first being A and the second being B, with 'そういえば' in between as a connector.