One picture can hold most of this word: a boy standing a step to the side, waiting to be needed. He carries, he fetches, he takes a message across the house. He is dressed for the place he serves in, and his whole job is to be near someone else and useful to them. Move that boy from a great house to a hotel, or to a wedding, and you have the other uses.
From the word’s history
The supplied source entry gives the word as page + boy. Page already names a young attendant, and boy pins the age, so the compound says, quite literally, a boy who attends on someone.
這份資料裡的來源條目說，pageboy 就是 page 加 boy。page 本來就指在人身邊伺候的年輕人，boy 再把年紀點明。合起來字面上就是「一個負責伺候的男孩」，和上面那個畫面完全對得上。
Wiktionary entry supplied in this packet (source_ref kaikki:3f6f69a190036ae4:1421687750:16702): 'From page + boy.'
登入就可以看每一支怎麼連回核心畫面。