[docs] last hidden state vs hidden_states[-1] (#26142)

* last hidden state clarification

* feedback addressed

docs/source/en/main_classes/output.md

@@ -40,6 +40,13 @@ an optional `attentions` attribute. Here we have the `loss` since we passed alon
 `hidden_states` and `attentions` because we didn't pass `output_hidden_states=True` or
 `output_attentions=True`.
 
+<Tip>
+
+When passing `output_hidden_states=True` you may expect the `outputs.hidden_states[-1]` to match `outputs.last_hidden_states` exactly.
+However, this is not always the case. Some models apply normalization or subsequent process to the last hidden state when it's returned.
+</Tip>
+
+
 You can access each attribute as you would usually do, and if that attribute has not been returned by the model, you
 will get `None`. Here for instance `outputs.loss` is the loss computed by the model, and `outputs.attentions` is
 `None`.