Honestly, I don’t know - I haven’t fiddled with the themes much on my Linux installations. All I can say is that currently, for the 3.x series, out of the box VLC looks very similar between Windows, Debian (KDE Plasma) and Linux Mint (Cinnamon) - all three of which are arguably different DEs.
A couple of other comments have flagged that this is the new 4.x UI, which certainly explains the difference.
Is this a distro-specific UI? It certainly doesn’t look like that on Windows, Debian or Linux Mint.
Doesn’t it use whatever theme you have your DE set to by default?
Honestly, I don’t know - I haven’t fiddled with the themes much on my Linux installations. All I can say is that currently, for the 3.x series, out of the box VLC looks very similar between Windows, Debian (KDE Plasma) and Linux Mint (Cinnamon) - all three of which are arguably different DEs.
A couple of other comments have flagged that this is the new 4.x UI, which certainly explains the difference.