What is the meaning of the lines in the Hadith of Ibn Mas'ud, which he narrated from the Prophet, peace and blessings be upon him: "This is man, and this is his appointed time (ajal)"?

The reciter explained the Prophet's hadith (definition), clarifying that the Prophet (peace be upon him) drew a square, then drew a line in its middle extending outside of it, and drew small lines inclined towards it. He explained that the middle line represents man, the square represents his encompassing lifespan, the line extending outside the square represents prolonged hope, and the small lines represent the ailments and afflictions that befall man. If one of them misses him, another strikes him, and so on until his lifespan ends.