Today I found that Power Automate Desktop doesn´t allow you to use correctly both "Wait for Image" and "If Image" actions on UI Automation.
It seems that you cannot select an image.
As a WorkAround, you can use these TextCodes to create actions if you need it.
Wait For Image
WAIT (UIAutomation.WaitForImage.ToAppearOnScreen Images: [imgrepo['NombreImagen']] FindAllImages: False Tolerance: 10 SearchAlgorithm: UIAutomation.ImageFinderAlgorithm.Legacy X=> X2 Y=> Y2)
If Image
IF (UIAutomation.IfImage.ExistsOnScreen Images: [imgrepo['NombreImagen']] FindAllImages: False Tolerance: 10 SearchAlgorithm: UIAutomation.ImageFinderAlgorithm.Legacy) THEN
Just capture your image first, name it and change "NombreImagen" for the name of your image. After that, copy text and paste it into your flow to get the well-formed action. If You need to put more than 1 image, just add a comma.
Wait For Image
WAIT (UIAutomation.WaitForImage.ToAppearOnScreen Images: [imgrepo['NombreImagen1']], [imgrepo['NombreImagen2']] FindAllImages: False Tolerance: 10 SearchAlgorithm: UIAutomation.ImageFinderAlgorithm.Legacy X=> X2 Y=> Y2)
Hope this can help anyone.