Struggling to convey the transformation in her pupils, the nurture group teacher at St Mark's Primary in Barrhead says: "I wish you had come a year ago. You should have seen what these kids were like then."
But there is no need for time-travel. The youngsters who just served buttered scones with charming hospitality at a big, yellow table in the Sunshine Room can go back in their own minds. "I used to get angry," says P3 pupil Kieran. "Then I would run out of class and hide under the jackets. "I don't do that now. I have ways to calm myself down."
He points to an image of a thermometer on the wall, coloured from cool blue to fiery red. "If I'm annoyed, I move this up one. If I'm angry, I move it up two. If I'm boiling mad, I move it right to the top."
Behaviour is a form of communication for children with strong feelings but no words for them, says nurture group teacher Katrina Flaherty. "To manage their feelings they need to identify them. If they have anger but don't know how to talk about it, they get frustrated.
"We help them to understand their emotions. It takes time. We watch programmes, read books, do role-play - which is why it's good to have two of us in the room, myself and the pupil support assistant."
With its comfy corner, play area, kitchen, table and bright space for schoolwork, the Sunshine Room is one of two nurture rooms at St Mark's in East Renfrewshire.
This is often seen as a leafy suburb, explains headteacher Gerard McLaughlin. "But we have wee souls that struggle badly in mainstream schools."
The reason lies in a well-established description of child development known as attachment theory, and its educational relevance is that normal school behaviour management will not work for some children. Not because they don't want to respond, but because they can't. Their brains have been shaped by early experiences to function less effectively for learning.
But this need not be lasting, according to educational psychologist Marjorie Boxall, who devised nurture groups in order to "create the world of earliest childhood in school and through this build in the basic and essential learning experiences normally gained in the first three years".
Their aim is to help children return to mainstream, typically within a year - which is exactly what happened to Craig (P6-7) at St Mark's. "I wasn't good at listening," he says, in the nurture room for older pupils. "I couldn't take turns. I had a bit of bad behaviour. I couldn't share. But I'm OK now.
"It was this room and the people that sorted me out. You got to talk. When we had tea and toast, we would sit down and chat. In the mainstream I didn't get the chance and would shout out. Now I'm back in class and I don't get any more time to talk. But if I get annoyed, I think about what I learnt in this room. I learnt a lot."
It's not always easy for children to find words for the effect of daily nurture room sessions. "I couldn't concentrate," says Sean (P5-6). "Coming here helped me a lot. I'm not sure how. It's just. magical."
There is plenty of scientific evidence now - not least from Glasgow City schools - for the effectiveness of nurture groups in sending pupils back to mainstream better equipped for learning. Nurture group teachers too return to class after a couple of years, and take with them a new perspective.
"Children's behaviour is a way of expressing themselves," says principal teacher Gillian Hamilton. "They are trying to tell you something is wrong. Just knowing that helps teachers. If you give them time at the start, ask what they need, how they are feeling, you can put strategies in place that save time later. It's a message we have been getting out to the whole school. You constantly reinforce it, as teachers come and go."
The nurture philosophy is so effective it shouldn't be restricted to special rooms, says Mr McLaughlin. "We are working on a whole-school nurturing environment. We have another group that learns social skills from the nurture teacher. We run CPD sessions. The two rooms come together for some activities, with older children acting as role models."
But there is no doubt that the special rooms, with their calm feel and comfy couches make a big difference. Or that the caring adults in them, who - in Boxall's words - "respond intuitively as a mother would to her own child at that early developmental stage", create a secure base for children's learning.
"It's like your own family," says pupil support assistant Katie Stewart. "They could never have laid on a meal for visitors a year ago, but they loved it today. We are even taking them out now on trips - to the fire station, the library, the cafe."
Even spontaneity has become possible, says Miss Flaherty. "We had a frosty morning recently, so we went out on the spur of the moment and drew spiders' webs.
"When they can do all these things, it makes you confident that they can go back to class and reach their potential. We are so proud of them."