Can you try to explain this Reigns/Lashley segment for me?

It was backstage a few weeks ago

Reigns: The WWE universe shouldn't cheer you

Lashley: (sounding surprised) WHAT??

Reigns: They boo me

Lashley: (sounding confused) Right??

Then it was the typical WWE camera work where the picture just stayed on them staring at each other for too long

A friend said that they were trying to show that Roman was jealous of the reaction Bobby had got, but that doesn't make any sense

After being booed for years, why would it bother him now and why would he only be jealous of Lashley, and not everyone else that gets cheered?