So, if I start out treating animals badly, and then later start treating them kindly, that would be evidence of a pre-existing valuing of animals which was simply being masked by circumstances. Yes?

Either that, or that your present kind-treating of animals is just a manifestation of circumstances, not a true value.

If I instead start out acting kindly to animals, and then later start treating them badly, is that similarly evidence of a pre-existing lack of valuing-animals which had previously been masked by circumstances? Or does it indicate that my existing, previously manifested, valuing of animals is now being masked by circumstances?

Could be either. To figure it out, we'd have to examine those surrounding circumstances and see what underlying values seemed consistent with your actions. Or we could assume that your values would likely be similar to those of other humans - so you probably value the welfare of entities that seem similar to yourself, or potential mates or offspring, and so value animals in proportion to how similar they seem under the circumstances and available information.