A two-slide explanation may need one diagram component to travel from an overview into a larger detail view. If it disappears and a similar component fades in, the audience may lose the visual connection. Build a small transition that makes the intended continuity easy to inspect.

Use a copy of the deck and choose one clearly recognisable shape. Give it a short label and a position away from other objects. Keep the first trial simple enough that an unexpected fade cannot be mistaken for an elaborate design choice.

Apple recommends duplicating the first slide with Command-D, then changing the position, size or orientation of its objects on the duplicate. Objects present on both slides participate in Magic Move; objects appearing on only one slide fade in or out by default. Select the first slide, then Animate, Add an Effect, Magic Move. The transition belongs after that first slide.

Prove continuity before adding complexity

Move the duplicated labelled shape to the opposite side on the second slide. Preview from the first slide and watch the shape for the entire transition. Its path should communicate that the same component changed position, rather than asking the viewer to infer a relationship between two separate appearances.

If the intended object fades, compare both slides. Check whether somebody deleted the duplicate and inserted a visually similar replacement. Return to the simple duplicated-object trial before adjusting duration or adding more effects.

The Fade Unmatched Objects option changes whether unmatched items fade or appear and disappear immediately. Switching it off does not turn a missing counterpart into a travelling common object. Keep that distinction visible while diagnosing the effect.

Check the explanation at speaking speed

Add the surrounding labels and context only after the single-object trial behaves as intended. Watch whether viewers have enough time to recognise the object before it moves and enough time to read its destination label afterwards.

Run the two slides in the actual presentation sequence. Confirm that the transition happens at the intended advance, not one slide later. Ask a colleague what changed between the two views without explaining the animation first; their answer is a useful test of whether the movement communicates the relationship you designed.

Reference: Apple: transitions and Magic Move in Keynote.