Reveal left side then right side in xaringan

Hello, I'm having a formatting struggle with xaringan. I would like to put key points on the right side of a slide, then reveal some picture or GIF on the left side. When I try to do this though, the picture gets pushed down below the level of the text, but I would like it at the top. It seems similar to this issue, but I know that one has been fixed. Reprex below. If this can't be done, I'd love to know more about why!

---
title: "reprex"
output: xaringan::moon_reader
seal: false
---

```{r setup, include=FALSE}
options(htmltools.dir.version = FALSE)
```

class: left, top

.pull-right[
- R

- is

- great!
]

--

<!-- I would like this up at the top, vertically aligned with the list -->
.pull-left[
![stormy R](https://github.com/allisonhorst/stats-illustrations/blob/master/rstats-artwork/stormyr.gif?raw=true)
]