Shaurya proposing to his ex because she's wearing a similar dress sounds so weird (and needless to say ITV cliche)...
But first off, is Shaurya Sabherwal that much of a chicken? To propose to a girl's back? Why do they have to ruin his image so much for the sake of drama?
And what do they gain by this track? Anokhi to witness the fake proposal and have a MU?
They can show her have a MU by letting her witness Shaurya and Shagun talking to each other where she picks just part of the conversation. And then she can ignore SS and not let him propose. Even that would work. But why show SS proposing to a girl's back ? Downright weak and dumb!