I've imported a photo and want to crop it. I draw a rectangle, turn it to path, select it with photo, and Clip > Set. Fine.

Is there a possibility to move the photo within the clipping frame, like in a viewfinder? It's sort of cumbersome to clip and unclip many times to crop a photo precisely.

Two methods:

1. Group the image before clipping, you can then move the object within the clip.
2. Do the above (best practice), activate the "Show Clip..." button in the node tool controls to modify the path.

@TylerDurden , thanks for pointing me in right direction. Apparently, we've got at least different toolbar setups, so for the googlers using Inkscape 1.1:

Go to Object > Objects... (will open Objects pane on the right)

Find the clipping path and the image in the list of objects, and select both.

Right-click the selection, and choose "Create clip group". The image will appear cropped.

In the Objects tree, there will be clipping group, containing the clip, containing path and image. Select either in the Objects pane, and move around to your heart's content.

I'd be surprised if the button has been omitted in 1.01. Might look different depending on the UI theme.

Here is 1.0.   The Node tool must be active.