Answer:
It could be because you where hack. Or there was something wrong with the site that stopped it from saying why it stopped.
Explanation:
Google Slides. Google has made a conscious effort to emulate many of MS Office's tools, and Slides is their alternative to PowerPoint. ...
DesignBold. ...
PowToon. ...
Slides. ...
ClearSlide. ...
Moovly. ...
Prezi. ...
KnowledgeVision.
The answer is a Scroll bar, the description fits perfectly because you need to move it to see more of the content you are viewing, and it wont be completely. when the item does appear completely on screen then the bar is relatively large and there is no need for scrolling, however the opposite occurs during when you cannot see all of it.