Is the distinction between an object and its representation of any importance in computer science?
Yes, it is one of the most important ideas in computer science.
It would be good to practice that idea. The diagram shows a vector and two coordinate frames; a light gray frame and an orange frame.
In the light gray frame the vector is represented by (8, 6)T. In the orange frame the vector is represented by (9.8, 2)T. Say that the axes of both frames are calibrated using the same units (inches, for example).
Using the first representation the length of the vector is:
( 82 + 62 ) = ( 64 + 36 ) = ( 100 ) = 10.0
Using the second representation the length of the vector is:
( 9.82 + 22 ) = ( 96 + 4 ) = ( 100 ) = 10.0