Scale and density.
Lisbon has 550,000 residents in the city and nearly 3 million in the metro area. Porto has 230,000 and around 1.7 million metro-wide. In practice: Lisbon has more distinct neighborhoods, more restaurants, more independent cinemas, more boutique accommodation options. Porto fits better in one mind — in four days you feel like you've mapped it. In Lisbon, that doesn't happen in two weeks.

