The most common and most likely answer to this crossword clue is the 10 letter word REFLECTION
I've seen this crossword clue in The Daily Telegraph
R
E
F
L
E
C
T
I
O
N
More clues leading to the result REFLECTION
- Contemplation of mirror image
- Cook left rice on -- something sent back
- Thought that’s returned when at one’s dressing-table?
- Official reading Mirror has this property
- Study reference shortly before lesson
- What woman applying mascara sees — pupils slip-up for example?
- Official choosing to ignore first instance of base work of The Mirror?
- Thought right choice has to include head of finance
Buddy explains!

The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does REFLECTION mean?
REFLECTION noun- The act of reflecting or the state of being reflected.
- The property of a propagated wave being thrown back from a surface (such as a mirror).
- Something, such as an image, that is reflected.
- Careful thought or consideration.
- An implied criticism.
- The process or mechanism of determining the capabilities of an object at run-time.
- The folding of a part; a fold.