Tree, extremely tall, in view in this source of illumination (6,5)

'this source of illumination' is the definition.
I don't know anything about this answer so I cannot judge whether it can be defined by this definition.

'tree extremely tall in view' is the wordplay.
'extremely' says to hollow out the word (remove centre letters) (only the extremes of the word are used).
'in' indicates putting letters inside.
'view' becomes 'sight' (synonyms).
'tall' with its centre removed is 'tl'.
'tree'+'tl'='treetl'
'treetl' placed within 'sight' is 'STREET LIGHT'.

'in' acts as a link.

Can you help me to learn more?