I presume you’re referring to Michigan, right? They already have the maximum number, by state law, of poll challengers - appointed before the election by both the state’s Republican Party and the state’s Democratic Party - monitoring the counting of the ballots. That’s a part of the state’s process.
Poll observers are allowed outside the event, but by state laws they can’t come in and try to interact with the counting or try to interact with the poll challengers or try to disrupt or distract the ballot counting process and poll challengers.
Part of what we’re seeing there now are some groups of people (some angry/upset) wanting to get in there...and by state law, that’s illegal, especially with the already appointed Republican and Democrat poll challengers already doing their jobs in there along with the ballot counters.
(I’m guessing the observers trying to enter the room either want to (1) prove themselves or make claims themselves of the ballot counting being fraudulent or (2) generally disrupt the process or cause chaos, either in the hopes of halting or in the thoughts that they might effect the numbers of the final count...either way, the officers there would have their work cut out for them, since all that would come of these observers doing such would be them getting arrested for breaking state law.)