dissolves between photos over video clip

[Ekzapple]

I have an interview subject who is an artist talking about her work. Over the video, I'm placing her artwork, so that she is speaking while you see the images. I'd like these images of her artwork to dissolve into each other, but the cross dissolve transition won't "stay" between the photos when I drag it there. Do I REALLY have to detach audio, get rid of the video and replace it with the photos in order to dissolve between the photos?? Hoping there is another option...
Working in IMovie 10
Thanks!

tried to find the "right" place to post this, so please advise if there is a better place.

 

[ColdCase]

The photos/video clips need to be butted up against each other without gaps for transitions to stick, if thats the issue.

 

[Ekzapple]

Thanks for responding... Yes, the photos are butted up against each other... but my question (and the screenshot shows it) is how to get the photos that are ABOVE the video clips to dissolve into each other. I've only been able to accomplish this by REMOVING the video clip and basically replacing it with the photos (and detaching the audio so that it's a voice over the photos.) Was hoping there was another way.

 

[ColdCase]

I dunno, it was just a suggestion. Seems to work fine, for me, in FCPX 10.4.2. Dunno why it couldn't also be set up in iMovie 10.

 

[Ekzapple]

Thanks anyway! Imovie is much more limited than FCP.