But what you are trying to do by the sound of it is to work your Sky as a secondary from the box elsewhere? Through a 'Magic Eye'? So the Sky remote works the box and this TV sees what the TV on the box elsewhere sees?
If so, I think it needs tuning in as a station see here
https://www.sky.com/help/articles/watch-sky-in-different-rooms
You'll have done most of this before so only one or two points need completing.
To view, I think you then need to select the channel you've tuned in, though I've no idea how to do this if it's a free view only TV.