百尺竿头更进一步 is a proverb that literally translates as: [Even a] one-hundred foot [tall] bamboo [can] progress even one [more] step.

Figuratively, this means: After having achieved a fair degree of success, one should try to do still better.

案山子 is a Japanese word that means scarecrow.

Colloquially, this can also refer to a figurehead within a corporation (stands tall with authority but has no backbone or power).

This can also be the Japanese given name Kagashi or the female given names Kakashi, Anzanshi, or Anzanko.

Sometimes the title 鳥威し is used for scarecrows in Japan, but 案山子 is far more common.

竹 is the character that means bamboo in Chinese, Japanese Kanji, and old Korean Hanja.

In Asian cultures, bamboo is often seen as a symbol of a noble gentleman (tall, straight, and honest).

There are also some multi-character bamboo words that regard individual bamboo plants, species of bamboo, bamboo as lumber, and edible bamboo shoots. However, this single character seems most appropriate for a wall scroll and covers the whole category of Asian bamboo.

南山之壽 is a wish for long life for someone. The first part of this Japanese phrase is “Nan Zan,” which means “south mountain.” This mountain is one of the good wishes, good fortune, and prosperity. The title is often used as a salutation of good wishes.

The third Kanji is just a connector, and the last Kanji means long life or longevity.

I guess you could translate this phrase as “May your life be as long as Nan Zan is tall.”