Sending pictures and have two small picture of pages at bottom or top of ipad when using internet or writing mails.

You have encountered the “Shelf” - this being a new feature of the now revised iPadOS multitasking environment. 

iPadOS permits you to have multiple “instances” of the same App - each instance being self contained. The shelf, when triggered, shows a thumbnail of each running instance of an App. 

For example, if you have three running instances of Safari, each with its own set of open tabs, you will see three thumbnails corresponding to each running instance of Safari - plus a button to open a new instance of Safari. Simply tapping a thumbnail will switch directly to that running instance of Safari. Each App has its own corresponding shelf.

This article from Appleinsider has a useful explanation of this new feature along with many of the updates to multitasking:

https://appleinsider.com/articles/21/08/12/how-to-master-multitasking-on-ipad-and-ipad-pro-in-ipados-15

The iPad User Guide is also a rich source of frequently overlooked information. The Guide is available both online using a web browser (such as Safari), or as an Apple Books download:

iPad User Guide - Apple Support

https://books.apple.com/book/id1567104892

You should note that the shelf is an integral component of the multitasking User Interface. It cannot be disabled.

Hi nilspdahl, thank you for posting in Apple Support Communities.

I wonder if your could take a Screen Shot of the issue and attach the image to the post. You can do this by pressing both the Volume Down button and Power Button at the same time.

Nevertheless, maybe try a Force Restart first to see if the resolves the issue then we can go from there. The following link explains how to do this in more detail:

https://support.apple.com/en-au/guide/ipad/ipad9955c007/ipados