poor result

[1701210370]

I use the model from https://huggingface.co/segmind/small-sd, but i found most of the result generated are poor
So what's wrong with my usage

import torch
from diffusers import DiffusionPipeline

pipeline = DiffusionPipeline.from_pretrained(
    "segmind/small-sd",
    torch_dtype=torch.float16)
pipeline.to("cuda")
# pipeline.scheduler = DPMSolverMultistepScheduler.from_config(pipeline.scheduler.config, use_karras_sigmas=False)

pipeline("A man staring ahead at the camera with a neutral expression",
         num_inference_steps=20,
         guidance_scale=7.5).images[0].save("my_image.png")

And this is the result, which is un-natural at all