It just looks creepily like Mara's right arm is bending backwards.
What a great pair of books though (Allegiance and Choice of One). Would have made a great Disney Plus series if that had been a thing back when they were released. Honestly, they could still do something similar. Cut out Mara (sad face) and the Luke and Han stuff, but a story about a group of renegade stormtroopers trying to make the Empire a better place by taking out pirate gangs and corrupt Imperials would be pretty awesome.