I am a native English speaker and would agree that "interesting to look at" is perhaps a little weaker than "promising." Maybe 20% weaker, as if there's a scale.

However, the transcript from the NY Times and BBC--not to mention my comment above--also has him saying "a great idea to look at" in the same response, which I do think is equivalent to 'promising'.

This is an inevitable consequence of telling others to be careful with their words.