That would definitely be a neat trick. I'll pass it along to our development team. We do have on the list to create a grid photo palette, so something like this might be needed. Auto-cropping is bound to cause barriers, though.

I have 2 good workarounds for you for now:
First:
1. Draw even sized nonplot rectangles on your plan where you want the images to go.
2. Use photo callout, scaling the photo up to best fall over the rectangle you drew.
3. Reposition it if needed.
4. Create a clipping boundary using the rectangles.
5. Move the Photo Callout name back to the photo - you can offset the rectangles to make yourself a quick snapping point?

Second:
1. Download photos directly to your computer.
2. Crop photos to a square in a photo editing software.
3. Make the even rectangle guides in you drawings as squares.
4. Use photo callout, and easily snap the square photos to the square guides. No moving of titles needed.

Option 1 is faster in the short term, while option 2 is faster long term since it's more effective to access the same photo for the same plant every time.