Their interactions are flirtatious but not over the top. You can see and feel the chemistry between the two characters - their facial expressions, rather than their actions, show their humor, annoyance, flirtation, etc. They like each other but they are holding themselves back from that.
There seems to be a lot of 'wanting from afar' in their romance. The studio seems to want the audience to be aware of the love interest but they want it to be a wholesome, slow moving romance. In the clips you never see the two actors touch, either. They may be sitting closely in the boat together but the