The "blunder check" option is for errors only. The level of these errors can be controlled by the "threshold" value that you can define. This threshold also applies to full analysis.
The threshold value is defined in terms of Pawn weights. A high value (say 200) will result in annotation of moves that are bad enough for +-2 pawn or greater change in evaluation, probably indicating immediate or imminent loss of material. A low value (say 30) will show also small improvements indicating where errors resulted in a positional loss equivalent to about a third of a pawn or more.
Full analysis is more detailed and can create references to the DB games and also add visual cues to the commentary it generates.
Both blunder check and full analysis show where the game was lost or won according to the threshold setting.
The full analysis helps in a more detailed study of how the game developed, additionally showing interesting possibilities both good and bad outside the threshold values. So, if one side plays the best move where there was a very tempting bad move (big improvement on small number of ply analysis but turning badly negative on higher number of ply analysis) it will often show the tempting bad move with appropriate commentary.