Hieroglyphic writings are simply ancient picture puzzles. In these puzzles, the images can represent the sound of an object or an idea associated with an object.
A modern picture puzzle is called a rebus. A rebus is solved by reading the sound of pictures aloud. When the images are read aloud, their meanings become obvious.
Try solving this rebus puzzle:
In this rebus all the images represent sounds. Read them aloud one-by-one … eye - bee - leaf - u, which might sound like 'I believe you' if you read it aloud a couple times. I added the plus symbol to show the sounds are linked as part of the same word.
Try this one:
In this case, the eye and the U represent sounds, but the heart doesn't represent a sound, it is a symbol for love. This is the Valentine's heart. While this heart symbol does not look like a real heart, it is an icon associated with St. Valentine’s Day and matters of love. So, if read this way, eye - heart - U, means 'I love you'.
Some characters can represent the sound of the object, others can represent the object itself or an idea associated with the object, like the heart. Egyptian hieroglyphic writing is similar.
Here’s one more puzzle:
This one uses images and letters to represent sounds, toe + key + the ‘oh’ sound = Tokyo, while the ‘ja’ sound + pan = Japan. Which means the solution is ‘Tokyo Japan.’