Show Off Or Riya
One will get the reward for that good thing. Any punish he gets will be just for that particular act of making the show off (If indeed it falls under it). Show off is purely based on intention and one can not peak into inner intentions. Doing good deeds while telling others do not necessarily be show off or Raya. We know in Surah Baqarah Allah did commend both payers of zakat: those that paid secretly and those that paid with announcement. That’s not necessarily a show off. When a person shows off they know it well themselves its bad and against the sharf of human being.