I did not mean to go this in-depth into it but uhh here I go.
Let us propose that the example mechs in the books are showroom models, that would be used to market to the public in both overt and covert ways. That is, they're made to make people ask, 'Can I get that feature/something like that feature on my mech?' With that in mind, how many of the SSC mechs from the core book (as I cleaned out my Comp-con recently and don't have anything else installed) are deliberately sexually provocative?
I think it's telling that the first step in this process is 'is humanoid toes deliberately sexually provocative?'. Because someone in SSC clearly thinks very highly of the combat application of accurately-articulated human toes. You can argue that it's made for Total Subjective Sync stuff to ensure maximum mobility in combat situations that mesh seamlessly with the own user's body... but that doesn't really pan out all the time, does it?
Black Witch: Strong start. Wide hips, a tightening around the waist, and a chest protrusion that is worked into the collar design but also the right size to imply breasts. Head very much has a humanlike shape. The fingers I'll forgive, they're good for high dexterity, but does a support/control frame really need individually articulated toes? Really? Also it's in shibari. 9/10 It Is On Purpose.
Death's Head: Very clearly and specifically nonhuman. No part of this is made to be a person, it's made to be a crab with a turret on top. Except for the small human-sized arms. That uh... I guess that's important to market some but it does raise question on why do it as human arms specifically? 2/10 I don't see it.
Dusk Wing: 1/2 size mechs are really just jumped-up power armor, but that established you can definitely see a feminine curve about the pilot's build that is emphasized by the dusk wing's tight fit. The dusk wings does not need to fit that tight. Another case of deniably developed chest plating. Arms are creepily long and skinny. Also, is it just me or do none of the three sets of arms actually line up with where the pilot's shoulders should be? 8/10 suspiciously shapely for combat armor.
Metalmark: Okay HERE is a bipedal bot made for dexterity in combat. Hooves, the connection between the legs and pelvis looks less like hips and more like robot pelvis, chest plate looks honestly aerodynamic and much like the legs the arms are attached in a moderately utilitarian matter. 1/10 this thing is here to murder all my friends.
Monarch: They tried to hide them behind the gun, but yeah, it has hips. Chest plate does not imply the feminine chest, but I do think it has the notion of pecs under there. And very wide shoulders. Head is inhuman, but that's really the only thing. Also, does an artillery mech need to have the grippers out? Even an agile one? I'm not convinced. 8/10, at least one gay man or straight woman is in on it.
Mourning Cloak: Thighs and lower torso are definitely not nothing, but that's really about it. Toes are spikes and as the mourning cloak is a close-range fighter focusing on precision strikes and dodging it has really the only good claim to the additional ground control and traction control being needed. Head is sure evocative, but not really of a human face, and the upper torso has a very sphere shape. Shoulders kinda neat, but again creepy long arms. 4/10 that deniability is plausible.
Swallowtail: Again, a spider with hoofed legs and a turret on it, just like the Death's Head. Again, just like the death's head, has a miniature set of human hands. Has a better claim to them than the death's head for if someone wants to do ranger stuff and do some forestry without leaving the mech, but it's odd that it's come up twice. 2/10 I can prove nothing.
Initial Results: SSC wants the interested parties to know that if they ask, SSC will deliver. They're saying it subtly, but they are. You probably have to know who to ask and/or where on the 'net to look, but 3/7 is too high of a proportion to be entirely an outlier. They'll never admit it in a public shareholder meeting, but they probably make a LOT of custom jobs with very specific hip and chest specifications.