In order to share your Presentation, it needs to fall below the size limit associated with your plan. For free users, Presentations must fall below 1GB and for Pro users it must fall below 10GB.
Presentations that exceed these limits can be presented on your device only.
The smaller your Presentation size, the better it will perform in the Web View. For that reason, we recommend resizing assets that are larger than necessary. For more information, see this article.