A: Include keywords in your filenames and separate with a hyphen!
The filename can give Google clues about the subject matter of the image. For example, my-new-black-kitten.jpg is better than IMG00023.JPG.
handmade-chocolate-byron-bay.jpg is better than chocolate.jpg
Whenever the "-" (hyphen) is missing, and you leave a space, or run the words together without any hyphens, or you use an "_" (underscore!) Google reads this as all one word ... kind of like supercalifragilistic etc etc! Pop the hyphen between each word, and allow google to READ the content in your image name.
# Help Google to discover all your images!