This may not be understood by some accents such as American due to these being British pronounciations.
Go stick your british superiority up your ass.
I'm an American living in Australia and I talk to British, Swedish, German, and Italian exchange students all the time.
No matter what country you come from, English shouldn't be hard to understand / interpret slang.
Maybe its hard to understand the pronunciations in your pictures because you're still in primary school.