How to show the exact difference of words in WinMerge?
You can indeed.
Open WinMerge, then under the Edit menu, choose Options:
This will open the Options (Editor) window, from here, select the Editor sub-option. In here there will be a section labeled Line Difference Coloring where you can select how the differences will be highlighted. To do what you're wanting, make sure to check the box View line differences and select the option for Character level:
This will highlight the characters that are different on each line.
Hope that can help.