Same AI face, 8 new scenes, 2 models. Seedream kept her 6 times, Nano Banana 4.

Who is the character?

We asked Soul 2.0, Higgsfield's portrait and UGC model, for a plain front-facing reference: grey background, neutral face, white t-shirt, and a short list of details that make a face recognisable across posts. It cost 0.12 credits.

One lesson came before the test even started. Our prompt asked for green eyes, a mole above the lip and a widow's peak. Soul 2.0 gave her grey-green eyes, put the mole below the lip, and drew no widow's peak. So we scored everything against the picture, not the prompt. Your character is whatever the reference image shows; the text you typed to make it no longer counts.

The five details we checked in every shot:

1. Eyes: pale grey-green
2. Freckles: a dense spray across the nose and both cheeks
3. Hair: copper, shoulder length, middle part
4. Mole: small and dark, just below the lower lip on her left side (your right as you look at her)
5. Jewellery: one plain gold hoop in each ear and a small crescent-moon pendant, nothing added

A shot "kept the face" only if all five held. Each scene prompt also repeated the details: "keep her face, grey-green eyes, freckles, copper hair with a middle part, the small mole below her lip, gold hoop earrings and the thin gold crescent-moon necklace exactly as in the reference". That's what a careful creator would type, so it's a fair test of the model, not of a lazy prompt.

Nano Banana 2: 4 of 8 kept the face

Nano Banana 2 at 2K, 2 credits a shot. Every image came back in well under a minute, and every one reads as a believable phone photo.

Seedream 5.0 Pro: 6 of 8 kept the face

Seedream 5.0 Pro at 2K, 2.5 credits a shot, same reference, same eight prompts.

What actually drifted?

Not the face. At phone size all 16 shots look like the same woman, and that's the point to take away: the obvious failure (a different person) didn't happen once. The drift was in the details that make a character recognisable over weeks of posts.

• Jewellery was the weakest detail. 4 of the 6 misses added or changed jewellery: both models invented extra ear piercings in side views (three shots), and Seedream turned the crescent into a loop once. Side and three-quarter angles were where it happened, which makes sense: the reference only shows her from the front, so the models had to imagine her ear.
• Freckles fade, mostly in bright light. Four shots lost most of the freckles: Nano Banana 2 three times, Seedream once. Three of the four were lit by bright window light.
• The mole never moved. In every shot where her left side was visible, the mole was below the lip on the correct side. Neither model mirrored her face.
• Nano Banana 2 ignored one camera instruction. Asked for her left profile, it showed her right side. Seedream followed it.

What does a usable shot cost?

Seedream costs more per image, but it wasted fewer, so per keeper it was the cheaper model in this test. The dollar figures use the Plus plan's monthly rate from our credits guide ($59 for 1,200 credits, about $0.049 a credit).

The whole test, reference included, was 36.12 credits, about $1.77 at that rate. If you'd only run Seedream, eight scenes and the reference would have been 20.12 credits for six posts you could use as they came back.

What should you do with this?

If you're building an AI influencer or a UGC spokesperson, a single good reference image already gets you most of the way. Three rules from this test close the gap.

1. Make the reference show every angle you'll use. Every jewellery miss happened in a side or three-quarter view, the angles our front-only reference never showed. A character sheet with front, three-quarter and profile views gives the model something to copy instead of something to guess. Our consistent AI influencer guide covers the character sheet and Higgsfield's trained Soul ID, which we didn't test here.
2. Write down your character's five details and check every post against them. Eye colour, a freckle pattern, a mole, a hairline, one signature piece of jewellery. Zoom in before you post. All six misses in this test looked fine at phone size; a follower who scrolls back through your grid sees them side by side.
3. Pick the model per job, not per habit. In this test Seedream 5.0 Pro held the details better and followed the camera direction; Nano Banana 2 was cheaper per image and made the single closest match (the UGC selfie). Our model guide has the full lineup, and Soul vs Nano Banana compares the portrait models.

If the character appears in ads, label it. TikTok's ad rules list content that "includes image, video, or audio that is either completely AI-generated or significantly modified by AI" as needing its AI-generated content disclaimer, per its ads help page. A fictional AI person in a product selfie is exactly that. Our UGC ads guide covers the rest of the workflow.

Our verdict

The headline fear with AI influencers is that the face changes from post to post. In this test it didn't: 16 shots across two models, eight very different scenes, and she's recognisably the same woman in all of them. That's a real change from a year ago, and it's why a solo creator can now run a character without a photoshoot.

What still drifts is the small stuff: freckles in bright light, jewellery in side views, an earring nobody asked for. Seedream 5.0 Pro got 6 of 8 shots fully right and Nano Banana 2 got 4, so Seedream was also the cheaper model per usable shot. Neither is good enough to post blind. Check every image against your reference before it goes up.