In my analysis of this simple conversation by the street scene in ‘Batman and Harley Quinn - 2017’ I have identified 7 animation principles that I think are used consistently or are very identifiable throughout this minute and a half long scene. 

I have identified: 

1. Squash and Stretch - changes in Harley’s face and neck when she talks to express emotions.

2. Follow Through - motions in Harley’s movements with her costume.

3. Slow In and Slow Out - in the movements of Harleys arms.

4. Arcs - in the curving motion way Harley swings her arms.

5. Timing and Spacing - in Harley’s more sped up playful or frustrated movements.

6. Exaggeration - in Harley expression to match her tone.

7. Appeal - with Harley’s playful personality and sarcastic attitude. 

• Squash and Stretch

Harley’s head and neck squash and stretch with her facial expressions to convey her emotional tone. The biggest and most consistent squash and stretch is her lips through this scene.

Her lips stretch in exaggeration and become oversized when she expresses; loud, proud, playful, and angry emotional differences and shrink/squash to an under exaggerated size when she displays other emotions like; surprise/shock, being upset, annoyed or when pouting.

When Harley’s does the ‘looney’ or also known as the ‘cuckoo’ spinning motion at her head, to simulate muscle movement the animation squashes and stretches her upper arm relaying the idea of bicep movement.  

• Follow - Through

Harley’s tails on her hood act as a secondary element and carry a follow through motion to the primary element of her head causing an overlapping action of her tails continuing to move/bounce from the momentum after her head has first initially stopped moving.

• Slow In & Slow Out

The strongest example of the slow in and slow out motion is when Harley taps at the side of the car. Here you can see the motion movement as she moves her hand at the car to the slowed stopped of hitting it, then the outwards motion before slowing to stop for just a moment with her arm out, then once again swinging back in to tap the car. 

But there are many examples in Harley’s arm movement that display slow in and slow out. Mostly in her crossing her arm together, or in the swing of raising and/or lowering her arms. These motions soften the action of her moving her arms and make the action more life-like in motion.

(Movements of Harley’s arms.)

This clip displays both: Slow In & Slow Out

As well as demonstrating: Arcs

• Arcs

Most things in real life typically move in arcing motions. Adhering to this principle ensures smooth and realistic motion in a character’s/person's movements. When Harley swings her arms outwards to the side, she moves in arc motions, moving her arms in an up and out manner.

As well as when she takes a swing at Night-Wing, creating a circular motion as she swings her arm straight and around.

There is also an arced motion in the way both Harley and Night-Wing fall into the car, they both hop up, over, and down, into the car.

• Timing & Spacing

Timing and spacing is used to both convey weight and emotion in this scene. As example; when Harley frustratingly starts to swing/sway pushing and pushing back and forth from the car, she moves slightly fast with each swing as she builds momentum, much as you would in real life.

• Exaggeration

Harley’s expressions tend to be quite ‘animated’ and exaggerated when she talks. When negotiating her deal/plan, she swings her arms around and sways her head back and forth as she speaks, exaggerating her motions to show her playful personality.

As well as her exaggerated pouting, with her head turned, looking away to the side and her eyes narrowed.

And lastly the facial exaggeration to express the idea of crazy/looney with the wonky cross eyes.

• Appeal

Harley’s playful ‘brat’ like personality of having a argumentative and sarcastic nature can make her a fun character when fleshed out and balance properly.

I think this scene has a good back and forth balance of showing many sides to Harley’s interchanging personality. Switching many times through this scene between her playful and sarcastic nature, to her more serious and annoyed attitude once knowing she can't argue or when she told Night-Wing back off.

As well as having some consistency with her general back story dropped in with her getting annoyed by the psychopath comment, due to her psychiatric training, then annoyedly correcting batman on sociopath.