mental representation

NOUN
21 LETTERS · STARTS WITH M

mental representation is a valid 21-letter word worth 24 points in Scrabble and 30 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS
M3E1N1T1A1L1R1E1P3R1E1S1E1N1T1A1T1I1O1N1
3 + 1 + 1 + 1 + 1 + 1 + 0 + 1 + 1 + 3 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 =24 PTS
DOUBLE WORD → 48TRIPLE WORD → 72
MEANING

What does mental representation mean?