PACK operation on a tuple (represented as a pair in Michelson, I get
$ ligo interpret -s pascaligo 'Bytes.pack((1, 2))' 0x05070700010002
The numbers 1 and 2 are serialized as
(1,2) is represented as
PAIR 1 2 in Michelson and
PAIR serializes to
0x07. So why are there two
0x07 values, and not just one?