The reason is simple，The mass of the head of the mech cannot be too heavy，The volume should not be too large，This results in the defense level of the head being far less rigid than the torso of the mech。

(nsfw:1.5),bad_prompt_version2-neg,ng_deepnegative_v1_75t,deformed,nsfw, naked, nude,large breasts,missing limbs,amputated,pants,shorts,cat ears,bad anatomy, no clothes,disfigured, poorly drawn face, mutation, mutated,ugly, disgusting, blurry, watermark, watermarked, oversaturated, obese, doubled face,b&w, black and white, sepia, nude, frekles, no masks,duplicate image, blur, paintings, sketches, (worst quality:2), (low quality:2), (normal quality:2), lowres, normal quality, monochrome, grayscale, bad anatomy,(fat:1.2),facing away, looking away,tilted head,lowres,bad anatomy,bad hands, text, error, missing fingers,extra digit, fewer digits, cropped, worstquality, low quality, normal quality,jpegartifacts,signature, watermark, username,blurry,bad feet,cropped,worst quality,low quality,normal quality,jpeg artifacts,signature,watermark,