It has nothing to do with sai imagination or her feelings. They wanted to show sairat skit so they showed it. Why would sai imagine virat side feelings when she don't even sure about his feelings for her. It's illogical to show that skit as sai imagination when in ost virat is saying u misjudged truth as lie and so on.
Yeah kinda of.. I have not watched the episode then would be able to review better..
You see the thing is that Sai missing her the most special person of her life..So she was imagining him every where and in everything..