Added comment to docs regarding ToTensor transform

docs/api/python/gluon/data.md

@@ -76,7 +76,7 @@ In the rest of this document, we list routines provided by the `gluon.data` pack
 ```
 
 Transforms can be used to augment input data during training. You
-can compose multiple transforms sequentially, for example:
+can compose multiple transforms sequentially (taking note of which functions should be applied before and after `ToTensor`).
 
 ```python
 from mxnet.gluon.data.vision import MNIST, transforms

python/mxnet/gluon/data/vision/transforms.py

@@ -245,6 +245,7 @@ def forward(self, x):
 
 class Resize(Block):
     """Resize an image to the given size.
+    Should be applied before `mxnet.gluon.data.vision.transforms.ToTensor`.
 
     Parameters
     ----------