[Test] Prompts for Skeleton Natural Body Type | 8 Conditions, 24 Images

Conclusions First

For prompts targeting skeleton natural characteristics (boniness, prominent joints, flat body, wide frame), bony was the most effective. Visible collarbone and overall body thinness were confirmed. lanky also showed changes in limb length and slimness. On the other hand, wide frame made the body larger overall (not just shoulders — the whole body became heavier), which is a different direction from skeleton natural’s “bony” quality. natural frame, angular, visible bones, and model frame showed little to no difference from the control.

Experiment Design

Base Prompt

White background + tank top + jeans standardized to clearly observe body silhouette.

A00: control

seed 1	seed 2	seed 3

Observation: Seed 1 is slightly broad-shouldered with a standard body type. Seed 2 is slim with narrow shoulders and a thin upper body. Seed 3 is also slender and standard slim. None of the 3 images show prominent collarbone or joint boniness — flesh coverage is standard.

A01: natural frame

seed 1	seed 2	seed 3

Observation: No difference from control. Seed 2 shows the same slim build with no change in joint prominence. “Natural frame” is likely being interpreted as “natural build” — skeleton natural’s specific characteristics are not appearing.

A02: bony

seed 1	seed 2	seed 3

Observation: Seed 2 shows the whole body becoming slimmer compared to control. The collarbone area is more prominent, and the line from shoulder to arm is thinner. The tank top feels looser, with increased body thinness. Seed 1 similarly shows a thinner and more delicate impression. The closest change to skeleton natural’s “bony” and “low-flesh” qualities.

A03: wide frame

seed 1	seed 2	seed 3

Observation: Seed 1 becomes significantly larger compared to control. Seed 2 shows wider shoulders and more volume in both upper and lower body. The tank top fits the body snugly with thicker arms. This is not the skeleton natural “wide from boniness” but rather a general shift toward a fuller figure. The change goes toward “larger-framed with more flesh” rather than “bony width” — not the intended direction.

A04: angular

seed 1	seed 2	seed 3

Observation: No difference from control. Seed 2 shows the same body type with no angular bone prominence or straight-line emphasis visible. No notable change in facial features or body type — not functioning as body type description.

A05: lanky

seed 1	seed 2	seed 3

Observation: Seed 2 shows longer limbs and an overall elongated impression compared to control. Upper body is thin with arms that look long relative to shoulder width. Seed 1 similarly shows a taller build with long limbs. This is close to skeleton natural’s “long limbs” and “model physique” aspects, but the boniness and joint prominence is not as pronounced as bony.

A06: visible bones

seed 1	seed 2	seed 3

Observation: No difference from control. Seed 2 shows the same collarbone visibility and body type as control. “Visible bones” may not be functioning as a phrase.

A07: model frame

seed 1	seed 2	seed 3

Observation: Seed 2 shows slightly taller stature and longer limbs compared to control, but seed 1 shows no difference. Any change present is minimal and inconsistent — cannot be considered a stable effect.

Summary

To produce skeleton natural characteristics, bony is the most effective. Body thinness and collarbone area boniness are stably achieved. lanky also contributes to limb length, but the effect is minor.

wide frame shifts toward “larger and fuller” rather than “bony and wide” — not appropriate for skeleton natural reproduction. To capture all skeleton natural characteristics, bony as the base combined with lanky, tall, etc. is the most realistic approach.

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