Seemed to be at home when one peeped through the window? (6,2)

'one peeped through the window?' is the definition.
I know nothing about this answer so I cannot judge whether it can be defined by this definition.

'seemed to be at home' is the wordplay.
'seemed' becomes 'looked' ('look' can be a synonym of 'seem').
'to be at' says to put letters next to each other.
'home' becomes 'in' ('he's home' can mean 'he's in').
'looked'+'in'='LOOKED IN'

'when' is the link.

Can you help me to learn more?