It looks like the character's stats wrong, given what we currently believe to be true about stat adjustment advancement.
Supposedly, characters add +1 to two different stats at levels 4, 8, 14, 18, 24, and 28. At levels 11 and 21, the character adds 1 to all stats.
So a 15th level character keeping two stats maximized should have +4 to two stats and +1 to the other four stats.
Standard array is
10, 11, 12, 13, 14, 16
This character appears to have assigned
STR 16
CON 11
DEX 13
INT 10
WIS 12
CHA 14
Dragonborn get +2 STR and +2 CHA for a starting array of
STR 18
CON 11
DEX 13
INT 10
WIS 12
CHA 16
Assuming that the player increases STR and CHA at every opportunity the stats SHOULD be
STR 22 (+3 from 4, 8, and 14 and +1 from 11)
CON 12 (+1 from 11)
DEX 14 (+1 from 11)
INT 11 (+1 from 11)
WIS 13 (+1 from 11)
CHA 20 (+3 from 4, 8, and 14 and +1 from 11)
But the character's STR and CHA are each two points lower. Is there any logical explanation?