I don't get it. Atri 'hates' Natsu but she still hugs him? Why?
Technically she hates him but she does not have to express the "feeling of hate" towards Natsu when she's a robot that was ordered to not simulate those emotions when she's with only him.
For why she hugged him here, it was simply to follow her programs: Satisfy her master. Hugging him is just a logical action that does it at the moment. This has nothing to do with "how she feels" or "her decision". She
supposedly cannot have any of these on her own.
If you pay attention, a lot of what she has done is robotic and somewhat human-pretending. However a few details have shown that she did make some very non-robotic decisions. This chapter has the best example: Going against Catherine's order for the sake of those she cares about. They are not even her master so this should not make sense for a robot.