Essential Clues

So I have this character in my head and I want to share him with my readers. I have loads of decisions to make now. How closely do I want the reader's image to tally with mine? How closely must it tally in order for my story to achieve maximum potential through understanding of this character? When should I create this image? Perhaps build it up over the first few pages, or in one quick, fell swoop?
One thing is for sure: If I allow my reader to create a false image and then shatter that image, they will be upset. The reader allows the author a little time to tease this image, to reveal this template, but they won't hold out indefinitely. Moreover, if the author doesn't control this image, the reader will make it up anyway.
There are easy options.
Mary had a little lamb, its fleece was white as snow.
Okay, not getting much feel for Mary here, but her lamb is pretty vivid.
And everywhere that Mary went, her lamb was sure to go.
Cool, a bit of characterisation for the lamb there.
However, more often than not, we don't really want to bog our narrative down with pages of info about a character (for reasons I'm coming to).

What is the essence of my character?
A lamb; has a snow-white fleece; follows Mary around (implies love, loyalty, etc.).

Let's imagine that Mary had another such devoted beasty.
I begin by mentioning that it has a long pink tongue.
Hmmm ... that image isn't really gelling in my head.
Okay, scrap that.
Mary's companion had fangs.
Still struggling.
Start again. Mary's companion had a stripy tail.

Wahay. Now we're getting somewhere.

---


Still working up new opening chapter to Tethered Light.


We had a right old verbal ping-pong match a few years back. In forging an image of Blinky in the reader's head, I had spread my clues very poorly. It's easy for me to picture him: I created him. I had unwittingly and unwillingly forced the reader to picture a kitten, when in fictional fact, he is a big cat, not far removed from a tiger.
Sure, I could've introduced him in such a way: Blinky was a big cat, not unlike a tiger.
But, apart from not being very classy, it really doesn't fit in with my limited third-person pov: Penpa knows Blinky is a big cat; Penpa has no idea what a tiger is.
I had successfully and succinctly defined Blinky's feline characteristics in the reader's head, through mention of purring, tail, amber fur and so on. But the moment Penpa rode on his back, I upset my audience and they had to reshape their mould.

The argument for me really came down to the disparity in the feedback, what with people missing or subverting pieces of information that seemed unimportant to them, but were absolutely key for me.
My readers began by imagining Blinky as a kitten.
I had opened with mention of sky-kittens, thereby planting a kitten seed in the reader's head. I made no link in the narrative between Blinky and the kittens. But the seed was there. Mea culpa.
This key point dissolved as readers began describing their mould as a cat. As Derren Brown will tell you, brains tend to take the easiest option. Unless my readers are hanging out with tigers, and understand that this is the norm, their default animal created from purring, stripy tail, whiskers and non-human name would probably be a domestic cat.

Whilst the distinction between kitten and cat was moot in terms of my failure to relay the large size of Blinky, it gave me lots of clues into how my readers were converting my words into images.
On the one hand, I was subliminally forcing them to make inappropriate connections.
On the other hand, they were defaulting; they were filling gaps and taking the easiest route to a mental picture, and I needed to plug those gaps.

Armed with this knowledge, I can now leave a trail of correctly ordered and essential breadcrumbs that guide my reader to the tiger-like form of Blinky.

At the time of writing, here is the order and essential content of the clues on the first page. I'm not happy with it just yet, but I'm having far more success than previously:

Penpa climbed from Blinky’s back and bounded to the edge of the precipice. (Opening line. Here, size is [relatively] defined. I stand a good chance of the reader understanding that Blinky is non-human, but it's not conclusive just yet. Note the mention of the word precipice lends itself to suspense, and Penpa's bounding to its edge sets up her character brilliantly.)
*
Blinky cast Penpa a look of disapproval. He swished his stripy tail and squinted at the sky ... (Here, the word stripy is causing me much anguish: it serves the single purpose of closing in on the tiger image, and I dislike single-purpose words or descriptions unless they are very important. The tail swishing demonstrates Blinky's irritation AND adds to the reader's construction of the Blinky mould.)
*
‘Such a sourpuss! ...’ (Penpa's disparagement subliminally adds weight to reader's understanding.)
*
Blinky’s amber fur bristled; his ears flattened and his eyes narrowed.

N.B. Other clues come from inferences such as interaction between Penpa and Blinky, and body language.
Of course, if this book ever does get published and features a picture of Penpa and Blinky on the cover, I'll be as covered as one can be!
I've posted more on this in preconceptions and essence.
[Tiger pictures from here.]
[Very angry cat here. Poor thing.]