In general, how good are Ofsted at picking when schools are putting on a show for them?

[Uniteed]

For example, a class having a science practical lesson for the first time in 2 years, whilst they are there?

It feels quite fraudulent.

“picking up” - can’t edit title!

Kids are rubbish liars generally so pretty easy for ofsted to see what's going on. The slt may pick kids to take the inspectors round but ofsted choose who to talk to. They might not intentionally let on what normally happens but they will spot it.