Lookahead Token in LR(1)

Question

P-> Q | ε  
Q-> m | m Q


S0:
S' ->.P, $
P -> .Q, $
P -> ., $
Q -> .m, $
Q -> .mQ, $

< Arrow from S0 to S2 moving with m>

S2:
Q-> m., $
Q-> m.Q, $
Q-> .m, $
Q-> .mQ, $

< Arrow from S2 to S3 moving with Q>

S3:
Q-> mQ., $/m 

Can someone explain how why the lookahead token "m" is in S3?

Thanks a lot for the help!