Asking for a friend.
Inside lemmy, yes. Pops up as a message.
Phone notifications would depend on your client. Voyager provides notifications for replies, but I’m not sure about others.
Depending on your instance, you may be able to get email notifications as well.
CapuccinoCoretto@lemmy.world 2 days ago
Top level comments, yes.
schnurrito@discuss.tchncs.de 2 days ago
It reproduces how reddit works. Or used to work because over there nowadays I sometimes randomly (unpredictably) get notifications for lower-level comments too, which isn’t an entirely useless feature, but very much looks like “trying to increase engagement”.
bamboo@lemmy.blahaj.zone 1 day ago
And notifications if you @ mention them in a child comment, like this: @tlekiteki@lemmy.dbzer0.com