They started of with saying that they were nervous; than Máxima asked 'what is the biggest difference?' but the children clearly didn't understand her question (one child said 'nothing') as their teacher had to explain that the queen was talking about the difference between being at school versus online classes. Then they asked which children did go to school during the lockdown (i.e., children of esssential workers).
Next, Máxima asked about 'the letter party' (some activity because they learned most of the letters of the alphabet - so, clearly this is the third grade (in the Netherlands they start counting at kindergarten (first and second grade), so third grade would be first grade in most countries).
The teacher starts talking a bit more when the queen asks about how the teacher was doing during lockdown (the teacher explains that sometimes the wifi wasn't working). And when she is about to leave one child raises her hand and says that she always sees (informal) 'you' on the news (on an I-pad); Máxima explains that that is what happens when you are queen 'it is what it is'.
In the latter conversations she talks a lot about 'how did the teacher do it?' (answer: it went well) and 'how long have you been using Chromebooks?' (answer: for years).