How long have you had the frog? Male white's tree frogs are more shy than the females. I had a male than was very shy and would hide out at the back but after a while he got braver and now sits out with the big girls lol. Your humidity is too high, they 40-50% is ideal, I never mist mine they absorb alot of water when soaking and have a thick waxy skin that holds alot of moisture so they don't need high humidity. Temperatures should be around 82 degrees. Take the moss out it's not safe they are very clumsy and will shove anything into their mouth if they see movement and if they swallow the moss they might become impacted and not be able to pass it. I use a reptile carpet with mine otherwise they get so dirty and make a huge mess. I find white's are alot more active if there's more than one in the enclosure, so maybe you should look into getting some more of them, although you would need a bigger tank as yours is very small and could be the reason why he isn't very active as he does need more space than that, 18x18x24 minimum for one whites. 12x12x18 isn't suitable for any frog, they need room to jump that size is too constrictive and should only be used for quarantine or froglets. Give him time he will adjust, settle in and become more active. Frogs take a while to settle sometimes and can take many months so you have to be patient. Playing the video won't stress him out so don't worry about that.

So you should
raise the temperature to 82
lower the humidity to 50%
remove the moss, change substrate to a reptile carpet (NOT the exo terra moss mat the canadian one is awful and the threads are very loose the US version is much better so if you go to Buffalo look out for one the US one is great and not available in Canada yet.)
get a bigger tank, 18x18x24 minimum
get more white's (3 max for a 18x18x24, they are so much more active in a group and a lot more fun to watch them interact with each other.)