[code-reflection] RFR: MNISTDemo UI tweak [v3]

[Adam Sotona]

> MNISTDemo UI adjusted.
> 
> ![screenshot](https://github.com/user-attachments/assets/e0054126-45e5-4eec-bf2d-707475dfc5b1)

Adam Sotona has updated the pull request incrementally with one additional commit since the last revision:

  Using MemorySegment instead of ByteBuffer

-------------

Changes:
  - all: https://git.openjdk.org/babylon/pull/327/files
  - new: https://git.openjdk.org/babylon/pull/327/files/6799f648..fbd4471d

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=babylon&pr=327&range=02
 - incr: https://webrevs.openjdk.org/?repo=babylon&pr=327&range=01-02

  Stats: 4 lines in 1 file changed: 1 ins; 1 del; 2 mod
  Patch: https://git.openjdk.org/babylon/pull/327.diff
  Fetch: git fetch https://git.openjdk.org/babylon.git pull/327/head:pull/327

PR: https://git.openjdk.org/babylon/pull/327