https://musicbrainz.org/doc/Release/Packaging says,

A box with a lid or an opening that contains the medium and other packaging, like posters and booklet containing lyrics. 

This was added without any discussion by https://wiki.musicbrainz.org/index.php?title=Release%2FPackaging&type=revision&diff=73414&oldid=73163

The request for "box" in STYLE-821 very clearly shows two products with lids.  Allowing boxes to have "an opening" without a lid encroaches on what a slipcase would be, which people have traditionally viewed as different from a box, and which record companies today market differently from boxes:

• https://tickets.metabrainz.org/browse/STYLE-225?focusedId=37300&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-37300
• https://tickets.metabrainz.org/browse/STYLE-225?focusedId=50340&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-50340
• https://tickets.metabrainz.org/browse/STYLE-1264

I would say box should be redefined to just be,

A box with a lid that contains the medium and any other items.

I'd also suggest getting a better image, as the current one is extremely low resolution and it's not clear it has a lid and isn't a slipcase.