"She found a little bottle on it and round the neck of the bottle was a paper label with the words
"Drink me"
beautifully printed on it in large letters. (...)
Soon her eye fell on a little glass box that was lying under the table :
she opened it and found in it a very small cake, on which the words
"Eat me"
were beautifully marked in currants".
(p.16-18, Macmillan Collector's library).
Indeed, in the movie the drunk Anastasia Seele (=Alice in wonderland) is brought to a hotelroom by Christian Grey. In the morning, alone in that room, she finds orangejuice with the the words
"drink me"
and a sandwich with the words
"Eat me".