For me, this scene was a beautiful start to Aarya's marriage...it set the tone of the whole relationship...
When Aarti was about to go and place her print, she could feel Yash's uneasiness...and she could understand it!!!! Eventhough at this time Aarti still had a negative opinion about Yash, she respected his emotions and did not place her palm-print on top of Arpita's as instructed by g3...
This clearly shows the emotional connection she has with Yash and this is seen throughout their relationship!!!!!!!
As for Yash, he did not stop Aarti from going to place her print on Arpita although he didn't like it as he didn't want to cause problems for her just as she's entering the house...
As always, Yash did protect Aarti from his family whenever he could...