When inserting an image into Impress slide show I do not know how to highlight it in order to rotate it.

[wbtodd44]

This occurs when I obtain a picture from a picture file.

[Hrbrgr]

Here is the basic way described:

https://wiki.documentfoundation.org/ReleaseNotes/6.0/de#Images_rotation

In detail: Click on the picture. In the sidebar under Properties, there in “Position and Size” a rotation angle can be adjusted.