。
Could you move aside, please?
Literal
Side [locative-へ] approach-[can you-てくださいませんか].
A polite request to step aside. 脇 is used here for 'side, the side'. 寄る ('to approach, draw near, move toward') — which can also mean 'to move aside' depending on context. ~てくださいませんか is the extra-polite negative interrogative request form, an elevated version of ~てください.