All the aliens given as examples in the first few pages are basically just humans with paint on and some very minor prosthetics.
It doesn't matter if it's got some tiny tentacles on it's head, or it's skin is blue, if 90% of it's body is identifiably human.
You're not finding an Alien lovey, you're finding the Human Form lovey.
The difference starts to come in when you get bigger changes to that human form.
When it no longer looks quite so human, it becomes weirder.
Take this Sangheili Elite from Halo, for example.

Ignoring the fact that it is wearing body armour, and that is typically not lovey.
It has an elongated face, uncahracteristic of humans.
It has 4 exposed mandibles for a mouth, which is unusual even in most mammalian nature and in Humans.
It's legs are more similar in structure to that of a horse, although in mirror. Once the upper-leg meets the knee, the lower leg bends backwards until the ankle.
Compare it to this leg, if it was mirrored.

What it comes down to is that aliens that don't share much of the human form are, as far as I can say in my own subjective view, less attractive and more weird.
Compare that to many of the alien races within the Mass Effect world, where you have much more humanoid Turians and Asari. They do have some key differences from humans, such as a rocky appearance or tentacle-like heads.
But their overall form is human.
When you get down to furries, that being Anthropomorphic Animals, it starts to enter a similar area.
The difference with Furries however, is that each one is usually based on a different animal.
And depending on that animal, it's relation to the human-form when anthropomorphosised is different.
For example, a furry based off of a bird is much less likely to appear human like.
You now start to have things like a beak (very unnatural and un-human), feathers (not a mammalian feature) and wings, which obviously are an entirely new limb that aren't found on humans.

The above image, taken from DeviantArt, is a generally good example.
It retains a considerable level of humanness, based on it's human torso and vaguely similar leg structure, but it's undeniably non-human, as shown by it's wings, feathers, beak, tail and feet.
I personally, find it difficult to see this image, or those similar to it, as attractive.
It's simply not human in nature.
But you then can easily enter a world where furries can look more human. While their actual animal counterpart may be considerably different in appearance to humans, it's anthropomorphic image can be very human in appearance.
The Wolf, and many other Canines for example, can show some similarity to the human form.

This image, taken from wikifur.com, is a good example.
The drawing style itself is cartoon-y in nature, which is a point I'll make in a moment.
This character has a regular human toros, and normal legs which stand up straight and unbent.
It's arms are of a normal human shape, and it's hands and feet, while based somewhat on canine feet and the padding around their claws, isn't too dissimlar from humans.
The lack of visible claws in itself aids the image, as claws are a non-human feature.
The biggest difference from the human-form is the furred nature of the character, and canine features such as a tail and upwards pointing ears placed upon and slightly to the side of the head.
The mouth is similar to a canine, in that it is on a snout, but this is short and doesn't protrude a lot.
It also doesn't show un-human oral structures, like a beak or long thin tongue.
Personally, I would find this image much more closely related to humans, and therefore much easier to find attractive in any loveual tense, presuming the image was designed more provocatively.
The concept of provoctivity is also key to the issue. The above Wolf picture is drawn very much in a cartoon style.
It focuses on a laid-back, almost caricature-style approach.
For some, this may be easier to mold into a loveual design.
For others, it is too similar to images appropriate for young children.
Compared to the Bird Image above, which features more detailed and serious designs, the two images are difficult to claim to be similar.
For that reason alone, it's a very difficult question to ask if Furries are lovey.
It entirely depends upon both the human form expressed within the image, the provocative design of the image itself (such as loveual actions) and the style of the image.
Not all styles work for all people.
Overall, I personally find that the weirder side of furry and alien loveiness comes about when the depictions are entirely un-human in appearance.
This is most obviously shown when you get furry creatures which are either mythological, such as Griffins, or those which are distantly related to humans or the mammalian line, such as Sharks or Lizards.
And then the same is equally true of aliens and their design.
Those which have extremely human appearances, like the Asari of Mass Effect, or the green-skinned Orion girls of Star Trek, or the Twi'Lek babes of Star Wars, will easily appeal to many people.
There is so little in difference between the two designs of these aliens and humans, that you can easily imagine the character as a human.
But the moment you stray into non-human territories, it all changes.
While there may be those with a special interest for such things, I think it would generally be accepted as more difficult to find this lovey.
