Inside the <style> tags you’ll want to create a new rule for the class smaller-image. Inside of that rule you’ll want to set the width to 100px. You can use the larger-image example above as a reference for how to do that.
After you have created the new rule then you’ll need to add the class to the <img> so that it is resized accordingly.
If you still have questions then please let us know but be very specific about what you don’t understand.