The mechanisms of DNA synthesis differs between the two new daughter strands during replication. This is due to the fact that:

one RNA primer attaches to the 5' end of the parent strand and the other primer to the 3' end.

Both daughter strands can't extend toward the replication fork because there would not be room for two DNA polymerase enzymes.

Both RNA primers attach to the 3' end of the template strands, which are at opposite ends from each other.

The DNA strands run antiparallel to each other and the DNA polymerase can only add nucleotides to the 3' end of the growing strand.