You can replace placeholder images in your presentation or images added via the Insert menu in two ways:
1. Paste from Clipboard
Copy the desired image to your system clipboard.
Select the image widget you want to replace.
Press CMD + V (Mac) or CTRL + V (Windows) to paste the new image.
2. Change Image Option in the Widget Toolbar
Select the image widget you want to replace.
Click Change Image in the widget toolbar.
Choose the new image from your device files