These images were likely made with a combination of controlled soft lighting, careful shooting, and substantial post-processing.

Most likely factors:

• Large soft light source: A diffused flash or softbox can create the smooth, even “liquid-like” shine while keeping shadows soft. The black background suggests tightly controlled lighting.
• Macro setup on a tripod: Close-up subjects need a stable setup and precise manual focus.
• Focus stacking: The unusually large apparent depth of field is probably from multiple shots taken at different focus distances, then blended in software so more of the frog and wood appear sharp.
• Moderate aperture: Something in a “good sharpness” range rather than relying on an extremely tiny aperture alone.
• Post-processing: Visible sharpening, plus boosted contrast and saturation/color work, likely help produce the crisp texture and rich look.

So the effect is not just one trick—it’s mostly soft directional light + focus stacking + sharpening/contrast/color adjustments in post.