Double "HEI" Chinese Word
The double "HEI" word is the most used word in any chinese wedding as it represents DOUBLE HAPPINESS for the couple. They are used sparingly throughout a wedding.
In the olden days, it used to be cut from a single piece of red paper and almost exclusively done by the tai kum jie. ( The person who's a wedding consultant to the family on matters pertaining to the rituals and ceremonies to be followed)
Nowadays it's available in many forms other than the traditional paper cut. There's the newer version where it's mass produced in the form of stickers to accommodate increasing demand for convenience and also the traditional red paper seemed to be difficult to source too.
Modern designs to the word also appeared in recent times just like the above picture.
Incidently, this picture angle is also a popular style used by a lot of actual day wedding photographers of which I noticed.