Harry and wife Meghan will be on hand to see athletes compete on the first full day of competition on Sunday, attending cycling and sailing events in the city.
Another onlooker was Invictus ambassador Curtis McGrath who competed in the Toronto games in 2017.
"She talked a lot about growing up in terms of this generation and the pressures of social media because there is so much criticism we experience", she said.
Following his terrible joke, Harry went on to give some words of inspiration to the residents down under, adding: "Our competitors have made it to these games - a lot of them travelling from thousand of miles away".
He continued, "Invictus has become about the example of service and dedication our competitors have provided to the world".
Prince Harry has fired up 500 athletes competing at the Sydney Invictus Games by praising them as the new generation of servicemen and women.
Meghan spoke about mental health while meeting with Bondi Beach locals on Friday.
They sat in the sand with a surf group that gathers weekly to discuss their personal struggles for what's meant to be one of the more intimate moments of the trip so far.
The Duchess of Sussex again championed Aussie designers with a $1,615 striped maxi dress from Paris-based Australian label Martin Grant, the same designer who made the trench coat she wore on Thursday and Tuesday.
Prince Harry and his wife Meghan are on day three of their 16-day tour of Australia and the South Pacific.
The two have already been talking about baby names.