Exactly this.

Also, they make some pretty big assumptions in the way they present the data. The main example of which being the magic date of June 27th, which they claim:

We can confirm that all documents published by the NHS preceding this do not include an under 18 age group, so we can therefore assume that the week of 20th June – 27th June was the first week that thousands of under 18’s started getting the Covid-19 vaccine...

This may or may not be even true. The UK government, to my knowledge have ever confirmed the exact date that people under 18 started receiving vaccines. Certainly, they were not being officially offered them, even in high-risk case, which was still being dicsussed in July.

The week of June 27th may simply be the first time the NHS/ONS started showing Under-18 as a separate category, seeing as prior to that, everyone under 25 was simply grouped together, as here on June 24th. Seeing as the government made no public announcement or set a date for under-18 years to begin getting vaccinations around this time, it seems a pretty big leap to me to assume that thousands of them suddenly got their first dose on or around June 27th.

This shows that the number of deaths between June 19th 2021 and September 17th 2021 among teens aged 15 and over were 47% higher than the number of deaths in this age group during the same period in 2020, and the increase in deaths began at precisely the same time teens started receiving the Covid-19 vaccine**.

Again, using the word precisely, when in fact we have no idea if under-18s weren't simply being counted in with the Under-25s before that, and, if so, exactly how many had recieved their first doses before June 27th, just shows how biased The Expose are when it comes to cherry picking the data to fit their preconceptions.