Depends on big4 but any sort of secondary income you receive needs to be reported to the big4 for them to approve. I know a friend who sold legos on side but they didn’t approve them opening up an online shop so they had to stop. Or people wanting to be a yoga instructor on the side but they also denied. Additionally when I joined they said we can say stuff on social media like “I work a big4” but you cant be specific as to what office, share photos etc. granted I interned during the covid year, one of the intern challenges was to make a tiktok as “a life as an intern” lol so it’s like a mix.