No different from slinging a Satchel Charge? In which case it's a tale as old as time.
For perspective ...
View attachment 132520
Comparitive size to other hand chucked explosives ...
View attachment 132521
Yes, I think it's different.
First, the website you linked to -- which is quite interesting btw, so thank you for that -- says that the Finnish factory-made satchel charge (FFMSC) in your attached photos came in three sizes/weights: approximately 2 kg (with 2 kg of TNT), approx. 3 kg (3 kg TNT), and approx. 4 kg (4 kg TNT). By contrast, according to the info I found online, TM-62 mines weigh around 9-11 kg and have 7.5-8+ kg of TNT or other explosive, depending on variant. In other words, *twice* the overall and explosive weights of the heaviest FFMSC.
To be fair, the TM-62 improvisation is a jury rig thing.
Second, as you correctly note, chucking a TM-62 into a building is an "off-label" use. The FFMSCs were designed for carrying, handling, and throwing, having a substantial wooden handle for those purposes. As for the TM-62, it would be like schlepping and tossing a 10-kg barbell plate.
So yes, I believe there is a meaningful difference in user experience between the TM-62 and a FFMSC. The TM-62 is twice the weight of the heaviest such charge, and considerably more awkward to handle. And after the emplacement or throw, the TM-62 user must get away from an explosion twice as energetic as that generated by the heaviest FFMSC.
The plate trigger pressure on an AT mine is usually beyond that of a human weight so throwing an armed AT mine is not likely to cause it to go off. Per one of the posts, the TM-62 is modded with a hand-grenade fuse which acts as the time-delay det to set off the hi-ex in the TM-62. But hey, if you have a crapload of AT mines and your enemy is short of tanks ...
[pedant] I've overwatched mine laying before. You emplace, you arm - you don't run away, you walk calmly away [/pedant]
Yes, I understand all that. That's why in my previous post I referred to "pulling the pin" of these modified TM-62s.