While the concentration of paracetamol is effectively the same, the bottle design and dispensing is different. It also appears the packaging size is similar, and there may be a reasonable reason why…
The bottle for babies comes with a syringe type dispensary kit, while it appears the kids one has a standard liquid dosing method, namely pouring contents into a measuring receptacle.
While the baby bottle may be smaller, packaging may be the same to allow packing of the dispensary kit.
The differences in package contents/dispensary methods could attribute to difference is cost even though the contents seem similar.
Unit pricing for smaller amounts is usually higher for many products. The baby bottle is possibly smaller as dousing amount is significantly less and potentially to reduce wastage from the contents expiring before they are fully used.
Many medicines marked as being for babies has a syringe style dispensary as it can be more accurate/easier to get the exact dose right which is important with babies where sensitivity to doses us greater. It would be reasonable to differentiate a product suitable for babies and kids, where dispensary methods are different even though contents may be the same.
It is also recommended that one seeks advice from a medical professional before giving any over the counter medicines to babies.