I think it's nice that Diana showed him a wedding that he could relate to instead of overwhelming him with more weird Amazon customs, since she's always about meeting halfway.
We're seeing that Diana (1) is worried about her own mortality, (2) is capable of making a mistake once in a while by rushing into a commitment with someone before she's sure of her love, and (3) actually has feelings of physical attraction for other people. This is very reassuring to me as a Wonder fan, because otherwise she's so far removed from humans that I can't relate. Show me someone who lives only for protecting the planet one-zero-zero-point-zero percent of the time and has to wake up alone every morning -- forever.
The whole thing was very sweet, fits with and resolves all the events up until now, and for me was perfect.