Turn off the ruler in your slide software and place elements by eye, and the title's position drifts a little from slide to slide. Unnoticeable on any one slide, but flip through the deck and the audience feels the screen "jitter."
The demo's ✕ places title, image, and caption by eye with no grid, so each sits at a different margin. The ✓ snaps the same three elements to the same columns of an invisible grid — turn the grid lines on, and every edge lines up exactly.
Checklist: does the slide master have a grid and guides set up, does the same kind of element start at the same coordinate on every slide, do images and shapes share the same margin value as text.
When to use
When merging slides made by different people into one deck, re-check alignment against the grid first.