Looks pretty good. I have a few suggestions:

You can move Cancel closer to the search progress indicator, to have them more connected in design.
You can probably add some Prev / Next buttons below the queue.
Since the queue appears to be a table, would it be possible to index them with a small column to the left of every entry?
You could probably either gray out the Remove / 'Delete' button unless an item is actually highlighted in queue, or add an X indicator next to a queue item when highlighted.
Could you have the queue items take long paths into account, or just show the file names?
And is there a particular reason why there's a column on the right side of the Queue string?

For the Config tab, when switching engine selection, you should have it maintain its striking blue color, instead of having it fade.

What are the differences between Clear, Restart, and Reset? Would it be possible to add a tooltip when cursor is hovering over?
What's that orange box below Restart?
Am I supposed to be getting image previews of the links in the thumbnail? Currently only shows input image?
When an image is in queue, and I click Reset, the image disappears from queue. After this, when I add another image through Browse, the image gets added to queue, but Run does nothing, and I can't click on it in `Queue.

Overall, looks really sleek. Has much higher potential than the shell UI.

GUI rewrite #34

Description