Either would be great for a small child. They are both very kid-friendly. We just got back from a stay at Pop. It was great for kids- and great for me, too. I have read a lot about the various resorts and Pop seems to be the favorite value for a lot of people. It tends to have better bus service and a better food court. On the other hand, if your daughter particularly likes one of the featured movies at Movies, then that might be more special for her. If she is in love with Toy Story or 101 Dalmations or Fantasia, then she would really like Movies. If she doesn't care much about any of those movies, then Pop might be better. There are some really cool huge statues of Baloo, Mr. and Mrs. Potato Head, Lady, a Mickey Phone, a giant Play Doh, a Mickey Phone, and a Big Wheel. I loved Pop because the decor was very nostalgic for me. I prefer it to the Movies decor, which does not feature any of my favorite movies.
From what I have read, if you select Movies then I would definitely go for a preferred room. Otherwise, you will have very long walks.
Pop would also be good because you can walk across the bridge to Art of Animation and see all of the great decor there from Lion King, Cars, Little Mermaid, and Finding Nemo.