There are two major factors at play here. Firstly the obvious vertical stretching (thinner faces) of the 2008 Blu-ray (yes, the same Blu-ray included in this Paramount 4K UHD) which are more apparent in direct comparison. The stretching was not there in the original DVD releases nor in the European DVD releases.
It seems to have occurred when making the last US DVD special edition where this stretching was first appeared.
Well, with direct comparison with the HDR-utilized 4K UHD we can see how much it is stretched. It's a lot, an error that was never rectified and remains in this 1080P 14 years later.
The second factor is also significant and is in regards to the 2160P 4K UHD transfer. Event Horizon was shot with the Panavision Panaflex Platinum... in 35mm. Where is the grain? It appears to have been removed and the resulting image is waxy morass, losing definition to the stretched
BD. Strangely the extensive, if dated, effects are eye-candy that distract from the soft facial close-ups. It's not that it looked horrible on my system - the grandiose effects helped the overall - but it is not particularly impressive or film-like 4K image with the grain removal.