The photo shows a smaller 12" or 16" wheel kids bike, with a single front brake and probably a coaster brake.
Sometimes the geometry of the bike (ie the angles of the head tube, and relative positions of axles etc) may not be the same as a larger bike or a different brand.
As long as the headset (bearings in the steering) aren't sloppy-loose then its probably just a cosmetic difference between two bikes.
As long as it rides okay then I wouldn't worry too much about it.
Sounds like the bike's headset bearings are loose.
Heres a scary looking cutaway:
And here's a closeup photo of a threaded headset. The washer in this photo is much larger than in the cutaway above.
summary there is too much space around the ball bearings at the top of the headset. To close up the extra space you will need some tools:
- Large adjustable spanner / crescent / wrench that fits the Locknut on top. A 12"/300mm spanner is about right.
- Something to hold the threaded race. In the photo its knurled so fingers or some sliding plumber's wrench with perhaps some cloth to protect the finish. Some have flats so you could use a second large spanner. Avoid vise-grips.
- Put a leg on either side of the front wheel while facing the saddle. This should support the bike.
- Back off the Lock nut a turn or so.
- TEST by squeezing the front brake lever with one hand, and hold loosely the other hand around the locknut area. You're trying to detect play between the frame of the bike and the stem.
- Try backing out the threaded race a turn and TEST again. The play should get a lot worse.
- Tighten the threaded race down too far and TEST, the play will vanish but the steering will be hard/impossible to turn left and right. This is because the bearings are being squished.
- Fiddle with the threaded race tightness until you find the happiest medium where there is minimal play but the steering still turns freely and smoothly.
- Once you're happy, use one tool to hold the threadded race still, and use the other tool to tighten the lockring down onto the race. If the race moves, it will mess up your tension.
- TEST again. If its not as good as you had it, work back and forth until the locknut is tight against the threadded race AND the play is gone AND the steering works.
This is an iterative process so its okay to loop around a couple times.
I bet the race ends up no more than an eighth of a turn from where it started. There is very little movement required to take play out of a headset.
If your bike's a little tired, then it may not be possible to completely remove all the play before the headset binds up and steering is compromised. Just aim for the best you can do.
I haven't gone into lubricating the bearings at this time - that may help too but is a bit more in-depth.
Further reading https://www.sheldonbrown.com/headsets.html and step 7 of https://www.parktool.com/blog/repair-help/threaded-headset-service and What tool is needed to adjust this headset on a children's bike?
Your bike is probably NOT a threadless stem as per How do I fix movement in headset