I have added images to both iPhoto and Aperture, identifiably different.
Nothing showed up so I closed all the apps, Pages 5.1, iPhoto and Aperture.
When I reopen Pages it finally sees my iTunes and iPhoto.
Still no Aperture nor Aperture images.
There are a couple more glitches as well.
If you use the Toolbar Media icon it pops down over the page and obscures the placeholder shape.
After you get an image into the placeholder shape, it is still a placeholder but loses the placeholder link in the corner. You only get the replace image pop-out after that by right clicking on the image, which works but means the UI is jumping all over the place.
You get the placeholder icon back by turning placeholder off then on again.
Definitely a work in progress.
Peter