Returning image from interpreter doesn't pause the terminal

### Issue summary

If you return a jQuery object with an image, the terminal is not paused while the image is loading.

### Expected behavior
Terminal should pause

### Actual behavior
The next prompt is available instantly.

### Steps to reproduce
1. Open https://codepen.io/jcubic/pen/JjLRGMr?editors=0010
2. Compare command `one` and `two`

### Browser and OS
NA