From 0 to 20 seconds of the clip the non-diegetic sound of background music is very upbeat and enjoyable, to the environment in the scene and to the audience behind the screen too. It creates a positive mood to the romantic dinner Ashton Kutcher and Katherine Heigl are having, Heigl's laugh at 10 seconds is a key to this scene too, it lets us know that nothing is going wrong and the two are purely having a good time...so far anyway. This is a perfect start to creating a dramatic change.
The music begins to quiet at 16 seconds into the clip, at this moment the audience does not suspect anything only that more dialogue would be entering the scene any second now. HOWEVER the audience later realises there is only no dialogue coming from Kutcher as he is miles away, instead starring at some guy who looks like he came out of the 'Men in Black' set (Mise en scene). At this moment (19 seconds) the atmosphere changes, the audience start to become curious to who this guy is, and the mystery begins to create the suspense.
The suspense continues throughout the rest of the clip, we unravel information as the clip plays on. When Kutcher sees this all in black guy (which i had a feeling was his dad) not only does the character get distracted but the audience too, we no longer accompany Heigl to the upbeat dinner she seems to be having as we are too busy thinking..."who the hell is that creep?" And so we join Kutcher to a small quest to find out. At 35 seconds 'men in black' guy leaves a book on the bench and the suspense begins to build, the audience wants Kutcher to GET THAT BOOK!...and so he does, at 43 seconds he excuses himself to go to the 'restroom,' Heigl on the other hand, has no idea what is going on as she is too distracted by the food. Kutcher gets to the book at 50 seconds and new information is revealed to him and to us. We know that the book was left there on purpose as the camera focus' out to the 'men in black' guy at 53 seconds, who was watching to make sure Kutcher got what he left. The camera focus' back to Kutcher and the book as he finds a note saying "cemetery 4pm - H" (your in big trouble now Kutcher, cheating on 'men in black' guy with Miss Eat-A-Lot).
The scene changes at 1:02 revealing to us, this man alone with Kutcher. We know that our answers will be answered very soon. We find out that Kutcher knows this guy, and Heigl is put at danger if Kutcher is with her (oh no, this makes the relationship a tad complicated). The suspense disappears as the audience gets their questions sl-iiiiiightly answered. For me the answer was a bit of an anti climax, 'men in black' guy should've said "Spencer, your mum was buried in this cemetery and i was given to do a voice over in the WHSmith advert. Now give me my french book back!"
...just kidding. The sudden change of mood and atmosphere at 19 seconds was really effective which is why i think the suspense worked. I may take the 'sudden change' into consideration for my group thriller opening sequence.