"दीवारें देख रही हैं।"
Translation:The walls are watching.
In the Armenian language we have an expression "The walls have ears", meaning "someone might be listening to us". Perhaps दीवारें देख रही हैं means "Someone might be watching us".
In the idiomatic sense. Indeed, many walls have surveillance "eyes" today.
I think this course can be a trouble for (only-)English speakers as there is no exact match for phrases and structures. For other languages it may make sense with exact translation or by close analogy.
As English speakers we can find the close meaning of awkward-sounding sentences. Expecting precise English translation is what creates frustration. I'm grateful for this generous course. I do intend to supplement it with further Hindi courses that teach me to better speak the language.