I made a couple of comparison images to show the difference in a scared dog versus a cheerful dog. The first one is very exaggerated, and the second one is a little more “normal.”
Feel free to save and redistribute these on other sites if you want. No credit needed as long as you don’t claim they’re yours and you link back here if someone asks where they’re from.
Lastly, under the readmore is a cheat sheet for reading his body language. (Disclaimer: I may have missed stuff. I am only a year and a half into “reading” fearful dogs!)