Transitioning from one POV to another within a scene

The first time it switched into the old witch's POV there was an extra space between paragraphs, a technique also used to indicate some time has gone by or the setting has changed. I'm going to copy a bit here as a demonstration—Lucy is the MC, a 13 year old girl living next door to Mrs Brackford, the witch, and has just snuck into her house. Starting with the last sentence from Lucy's POV before the switch:

Lucy turned and quietly walked back down the hall, then slipped into the bedroom and bathroom beyond. (I'm a little surprised the editor didn't change this—the story is from 1995, when I think Bed Bath and Beyond was a very well-known franchise.This is where the extra space between paragraphs is.)


Ruth Brackford started the laborious journey upstairs. The climb seemed to require more effort every day. She thought idly of having her bed moved downstairs. (Nicely done. It begins with an 'external' shot of Ruth climbing the stairs, as if the camera is now out of Lucy's head and momentarily in an Objective viewpoint. The second sentence isn't really interior to her head yet, but is very close. It's a transition from seeing her climb the stairs, through the way it makes her feel, and then into her head. 'The climb seemed to require more effort every day.' is not as interior as 'She thought idly... ')​

There follow 3 paragraphs from Mrs Brackford's POV, ending with her smearing a vile potion she just made in the kitchen onto the face of a small effigy of Lucy's father. I'll pick up from the end of this part:

"Tastes wonderful, doesn't it?" Her laugh was a thin crackle. "Ipecac and sour cream, mashed maggot and rotting meat, everything needed for a healthy lad like you." (No extra space here)

Lucy watched from where she hid concealed by the altar curtain, terrified but elated when Old Lady Brackford's thin ugly laughter changed tone. She began to gasp and raised one hand to her throat. (It's a little confusing here—who gasped? But it doesn't seem likely to be Lucy, and this confusion actually plays into the moment, because something important is about to be revealed.) Lucy hadn't been able to remove all the residue of her father's body from the doll, but she had managed to add a good number of discarded grey hairs to the sticky patch. (A moment ago she had looked in the bathroom and seen hair all over the sink and floor.) Enough of them, it appeared.

Ruth Brackford gasped and bent forward, shoulders heaving as her stomach abruptly tried to empty itself. She maintained control, but swayed as she turned, lurching toward the door. When she was out of sight, Lucy emerged from her hiding place, snatched up the doll, and headed for the door.
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I feel like the shifts are very well handled, easing the reader into and out of the different POVs deftly. This is completely different from the beginner's way, which is to just jump from inside one person's head to inside another one with no transition (AKA head hopping).