If you ask anyone who knows anything about Yu-Gi-Oh! -- or indeed, anyone in-universe -- they'd be hard-pressed to name someone more egotistical and self-centered than Seto Kaiba. Lacking anything resembling modesty, this man does nothing by halves, from renting out an entire city for a card game tournament to launching Duel Monster cards into space for the express purpose of teaching aliens to duel (which may or may not have actually paid off). With that in mind, it should come as no surprise that he eventually takes the next step in his quest to be the most extra character in the franchise: turning himself into a Duel Monsters card.
Granted, this isn't the first time he’s been a Duel Monsters card -- in Duelist Kingdom, for example, Pegasus turns him into one as the penalty for losing a duel against him. But there is a marked difference in being turned into a card and creating a card in one's own image -- which is what the self-explanatory Kaibaman is.
It's not like Kaiba can deny this, considering Kaibaman's outfit is identical to his iconic Battle City outfit, only with Blue-Eyes armor attached. And the card's special ability is one that Kaiba would definitely prize: when tributed, this card enables the player to special summon one Blue-Eyes White Dragon from their hand. Considering Blue Eyes usually requires the sacrifice of two monsters, this cuts down the summon time exponentially and lacks the issue that the "Lord of D./Flute of Summoning Dragon" combo has, where it allows the opponent to summon any dragon-type monster from their hand as well. So, at face value, Kaibaman seems like the perfect monster for Seto Kaiba, whose main mode of attack is to get his Blue Eyes on the field as fast as he can.
That said, you'd think he'd have given Kaibaman more impressive stats. At 200ATK and 700DEF, it's kind of weak for a three-star monster. Kuriboh has more attack power than Kaibaman. For someone who values attack power over all else, it's kind of strange that Seto Kaiba -- full of himself enough to make a card that looks just like him -- would make said card so weak. It's not even like he could combine it with "Crush Card Virus," since that requires the tribute of a Dark-type monster and Kaibaman is a Light-type monster. The fact that, in the anime, he can be tributed on the turn he's summoned is really the only way he stays on the field long enough for his effect to work.
This lesser attack power doesn't stop Kaibaman from having his namesake's ego or his voice, for that matter, since in both the Japanese and English versions of the anime they share a voice actor. He's also just as skilled in a duel, as during his appearance as a Duel Monster spirit in Yu-Gi-Oh! GX, he handily delivers Jaden's second defeat ever, ending the duel in six turns. And throughout the duel, he exhibits Seto Kaiba's trademark snark and runs his deck. He even summons himself, which is totally a Kaiba move. If nothing else, Seto certainly channeled his attitude into this card.
So why did Kaiba make this card and why is it anime-exclusive? The second question can be easily answered by pointing out how quickly the card would be slapped on a ban list. Summoning a Blue-Eyes as soon as you play it? Just a tad overpowered -- exactly how Kaiba likes it. As for the first question, it doesn't get any more Seto Kaiba than making a card patterned after yourself. Kaibaman is fully, quintessentially, Seto Kaiba, down to the smallest details -- and that's what makes him great.