To further elaborate on this idea, and then the technicalities of it and its relative benefits to a completely human body, take a look at this harpy (image one, very very cute, artist is rnd.jpg) and imagine that you want to build something along the lines of this model.
The biggest and most apparent differences are, of course, the wings and the legs, which you may think would complicate the build further, but it's the contrary, as it would eliminate;
1. The needs for human hands and feet, which have just a fuckin shitload of bones in them, which in turn makes for much more complex construction. for instance, a single bird's wing (image two) only have three joints from the main connector at the 'shoulder', compared to humans, who have 27 in just a single hand, a much smaller and dense space. The legs (image three) have even less, with a single 'ankle' joint and a 'knee' joint, although depending on the style of feet for the bird species the toe phalanges (up to five a toe in some species!) may give some trouble, but that could be circumvented by simply creating the foot of a species with less of them lol So not only would the construction be much easy, but it would have a higher relative quality.
2. The problem of the uncanny valley that could be triggered by limbs and/or appendages trying to perfectly resemble those of humans and failing. We have such a response to the uncanny valley because we're socialized with humans to notice even the slightest thing that's off, but we don't have nearly the same capability with other species, on top of the anatomy of certain ones being much easier to deal with.
Both those points are pretty applicaple to several different species of monster girls as a whole, and make them, in my opinion, a much more viable alternative in this stage of robowaifus, much in the same way some anons push for RWs that go out of their way to not appear human while still being endearing.
(shoutout to /monster/)
So on the other side of this proposal is the actual interaction and how such things could be done for max 'oh god oh fuck I wanna cuddle you'. Both for capitalistic budgeting/marketing and also because I would want one for myself.
So essentially it would be a mute, as I've said in my previous post, because frankly the technology for irl, face to face conversations isn't there yet, and probably won't be for quite a while.
So all that time that would be otherwise spent on the 120(!) joints in the hands and feet alone and the voice output system could instead be pumped into two main interaction systems that feed into each other for a wholly more immersive waifu experience.
Firstly, the voice recognition system. For just a basic setup, let's say that, before your customized harpy petwife shipped out, it has both it's own name (picked by the owner) and the owner's name/face already calibrated into it.
It would use a kind of emotional recognition system via voice (and likely a small visual system as support) to know when to perform various actions. Say, you're feeling kind of down, it'll come waddle over and cuddle up to you, etc, etc
And this is where the expressions start to come in.
So secondly it would have a complex series of body language and facial language, paired with a haptic systems. Say if you were to pat its head, it would have give a more content expression, but if you were to suddenly stop after a very small amount of time it may try to cozy up and look up expectantly to you in an attempt to get more. Or, alternatively, if you don't pay it enough attention, it may become dejected (you monster) and ruffles its feathers at you, which reinforces your desire to take care of it and incentivizes daily bonding.
If you hold it in a standing position long enough, it may wrap its wings around you, or if you hold around it in a vertical/sleeping position long enough it goes into sleep mode. etc, etc.
And you can fuck it, of course.
I've got a couple ideas for aiding with the facial emotiveness, which is the most important thing in RWs, most notably shifting eye colors depending on the 'mood' wheel (corresponding with the color wheel), but I really don't know how else to go about it for the anime aesthetic, and it seems neither does anyone else, barring just a screen for a face.
The Mirai head (image four) from Furhat Robotics/Bandai Namco is a step in the right direction, but I'm still kinda worried that this aspect is lagging.
In closing, again, this is more just a baby step towards a total interactive relationship with full voice capabilities, but it's more important to establish the market for robot companions (not even necessarily in a romantic sense, although that's most likely how it'd turn out, but in a pair bonding sense) as a way to bring in investors, and therefore competition, and therefore innovation, resulting in more and more advanced upgrades to your once-mute bird wife until she can somehow make you miso soup with her bird... hands... every morning and reaffirming her love for you verbally
I went in pretty deep, probably should've just made a thread about monster girl robowaifus, but I didn't want to bump one off the board
(image five: endgame)