figure changes size at end of loop if drawn dynamically

As per the title, consider the following snippet:

```
import time
import ipympl
import matplotlib.pyplot as plt

fig, ax = plt.subplots(1, 1, figsize=(5, 5))
data = []
plt.show()
for idx in range(4):
data.append(idx ** 2)
ax.clear()
ax.plot(data)
fig.canvas.draw()
time.sleep(0.2)
```
and this is what I get running it:


I used `plt.show()` at the beginning of the loop because nothing gets drawn otherwise.
Is there a way to avoid this?

Start by running the provided Python snippet in a Jupyter Notebook with ipympl and observe the figure resizing during the loop. Trace the dynamic draw behavior used by the example, then verify that the figure keeps its intended size across all four updates.

Written by the indexing model from the issue text.