That's just the game loading. It can take a while to fully load in sometimes.
If this happens before you've reached the nexus, that's just because the game hasn't fully loaded yet. If it's after that, it's probably a mistake. Please fill out a feedback form reporting it, thanks!
Check if an exclamation point in a circle icon appears in the bottom left of the slideshow menu. If it does, click it, and enable autoplay. If no option to enable autoplay appears, refreshing the page may help, but is not guaranteed to.Â
This is usually the result of switching between slides too fast. Clicking on the diary and then exiting out of it will usually fix the problem, but if it persists, you may want to reload the page.
Google Slides currently has a bug (as-of mid 2025) where images simply won't load sometimes. Sometimes this happens because the game itself is still loading in, sometimes it's a result jumping from an early slide to a later slide too fast, or as a result of clicking between slides too fast, especially for slides with gifs. Sometimes it's also just random. Reloading the page and clicking slower may help. Switching browsers may also help. Regardless, if this happens to you, please fill out a feedback form reporting which slide numbers were affected. Thanks!
As a general note, the Google Slides version is more prone to issues than the Powerpoint version. If you continuously run into issues in browser, I would recommend trying the downloadable Powerpoint file instead if possible.