Edge hits on target frames, rocks, tree limbs and any other solid object downrange can re-direct the ball.
We shot at this setup with handgun, rifle and shotguns and so far I've reclaimed several pounds of lead and melted them into ingots. Almost all jacketed rifle and pistol bullet cores are pure soft lead as well as most lead shot so they can be cast into great muzzleloader balls.
I'm making a video of us shooting this setup in a "shoot house" 3 gun match using multiple "tire targets" We used AR15's, shotguns and handguns at 15' or less (frangibles in the AR15). I salvaged a LOT of lead from that match. I will try and post the video if I can ever get my internet to work properly. We ran 120 shooters through this stage with zero injuries.
It's a given that rocks,tree limbs etc down range can re-direct the ball, I'm pointing out to the people that don't know (plenty of them) that an edge hit on the target they set up may send something up in an arc and hit something they don't want hit.
I was referencing the lower picture you posted more so as the gap around the steel looked like it leaves a space for an edge hit ricochet,
I also noted that I thought the target was a good set-up, more so if the steel is in the center line of the tire to catch the 360 deg spatter.
Steel targets can be shot at 15 feet (5 yards) and Iv'e seen it many times but it does not make it safe, a steel plate inside room distance ("shoot house") with no cover over the face of the steel is asking for a hospital trip for somebody (seen this a few times also).
For Ref; I ran (match director) steel challenge matches for 8 years, some of the first Ruger rimfire steel, big GSSF matches over 500 shooters, 3 gun for 12 years, IDPA local/State, stage design and set-up for a few Nationals, USPSA matches, ICORE matches, cowboy matches, I teach local and federal L.E. SRT Teams, teach military teams and I set up the shoot houses for this.
I own a range that held some of the matches noted, I have 3 steel bays with each bay holding 30 targets, 3 paper bays (8 shooters each) and a rifle range with 50/100 and 175 yard target walls. I reference this because shooting is what I do.
I'm an instructor (as above), USPSA Revolver Grand Master (all other div master), IDPA ESP Distinguished Master (all other div master) , 3 division ICORE Master, one second club, etc.
I only comment on this subject because I have seen countless times that people do not understand what happens with bullets, what they do after the target is hit, many think it all stops after the hit, many think it stops when the ground is hit or water regardless of angle. I had a friend and S.O. at a match catch a ricochet from an angled steel plate that was 7 yds away (he was standing next to the shooter) that passed between his ribs, a hex head bolt holding the plate was all we could come up with for the cause.
P.S.
Most lead shot from a shotgun is not pure lead it has antimony to make it hard, often used by casters to harden a batch of lead.