I think the pictures don't do it justice (maybe b/c of the short front?). Strictly by dimensions, it's bigger than the Golf.

From wikipedia:

ID.3:

  Length 4,262 mm (167.8 in)
  Width 1,809 mm (71.2 in)
  Height 1,552 mm (61.1 in)

Golf:

  Length 4,255 mm (167.5 in)
  Width 1,799 mm (70.8 in)
  Height 1,452 mm (57.2 in)

Also much longer wheelbase (2,765 vs 2,637).