Copy and pasting an image from one instance of ArcGIS Pro to another displays a blank element template. The image path is retained, but the image is not displayed unless the path in the element Properties is selected.
This is fixed in ArcGIS Pro 3.1. Note that this issue does not occur in ArcGIS Pro 2.9.x and prior.
解决办法
Right-click the pasted image and select Properties.
In the Elements pane, notice the Simple Path (local path, UNC path, or URL) check box is still checked. Click the folder next to the Simple Path(local path, UNC path, or URL) field.
Re-select the same image from the Insert Picture window.