The mention of wanting to have a memory of the scene reminded Wolfe that he had new knowledge that could be applied in this situation. The memory crystals were a matrix of elemental magic, so he could create one easily enough, and he now had the spell to store memories in them.
Creating something as elaborate as the one in front of him would need a lot more practice, but Wolfe thought that he could do one scene from his recent memory.
So, with a moment's focus, he created a shard of crystal with Lightning Magic and then started to imprint the pattern on it to store the memory of the moment that Katerina had hugged Kira and buried her face in the fluff of the Kitsune's tails.
That went more smoothly than expected, so he added one more memory just to tease Mary with. The memory of her in a fluff frenzy, looking for Katerina while the girl hid behind a shelf in the library.