Thank you very much for your reply. I already tried that option as well. However, it still doesn't work.
From the mobile application it doesn't show the images and from the computer it doesn't either. I have noticed that there is a relationship between having the SharePoint tab open in a tab and the PowerApps tab.
When I load the application without having opened a tab to SharePoint does not show the image:
When I open the document library in a tab, all images are loaded into PowerApps:
I don't know what the reason for this might be. Thank you again.