For me the scene was pretty straightforward that it was her discomfort - Simply because that room was a private space - of Shaan and his Natasha and she was there... it was intruding into someone else's space and when u have such a huge photograph hanging right there.. it like throwing it in your face that you are in someone else's room and yeah secondly... it would remind her about all the incidents that ensued after she arrived in Mumbai...
For her , what holds utmost importance is that respect she holds for Shaan and his privacy - she respects that and that indicates she respects her own, which Shaan is aware of and he respects her privacy too. If you notice they dont get into too much of their lives, associated with Suraj / Natasha!
Infact , I really liked the fact that Shaan was aware of her discomfort and reacted appropriately..all to ensure she is comfortable in the room, given that they have to spend the next few days there ...
For me that is the most beautiful display of the respect they had for each other's private space... I dont think anything else can come close to what was displayed yday , to express the respect that a couple has for each other!
just my two cents...