Two AI video systems can make equally impressive first frames and still fail for completely different reasons. Looking at the type of failure is more useful than asking whether a clip simply looks good.
Identity drift
A face, garment or object gradually changes as the sequence advances. The first and last frames may look individually plausible while no longer depicting the same subject.
Motion without mechanics
The model understands the requested action but not the physical chain behind it. Feet slide, hands miss contact points, liquids ignore containers or a camera move changes the geometry of the room.
Continuity under pressure
More subjects, occlusion and fast movement increase the burden on temporal consistency. BlinkX comparisons therefore include controlled stress tests, not only model-friendly beauty shots.
Refusal is also an output
A useful review records when a lawful prompt is refused, softened or silently changed. Restrictions are documented separately from visual quality so creators can judge whether a model fits their intended workflow.