Shrines are a staple of the Diablo games and that'll be no different with Diablo 4 shrines. In previous Diablo games Shrines are randomly generated objects that grant the player who clicks it and sometimes also those nearby a temporary buff of various properties. They've always worked in this way and although Blizzard have not mentioned Shrines yet it's likely Diablo 4 Shrines work in the same way again.
When the shrine is clicked a buff marker appears above the player's head to show that the effect is in place. Shrine effects last two minutes. There are different markers depending on the shrine buff.
List of Diablo 4 Shrines
|Greed||"Wherever the brave strike, riches Follow"|
|Lethal||"Fate guides the deft hand to strike true."|
|Vampiric||"Blood begets blood"
You are healed when dealing damage. Note: Buff marker glows as player is healed.