Your mobile should be waterproof in fresh water (not waterproof in SALT water and less waterproof in heavily CHLORINATED water). If you think that you had all flaps firmly closed and you took that picture in fresh water, then visit your nearest local support center and ask for a Vacuum test, it will be replaced/fixed if this test fails.
/t5/FAQ/How-to-get-your-Sony-Xperia-product-repaired/m-p/991374#U991374
