Parish registers in the Church of Scotland tend to be less well organized and structured than their counterparts south of the border in England. Particularly in highland parishes, sometimes no parish records survive at all from the eighteenth century or earlier. This is due primarily to the fact that the ecclesiastical laws pertaining to the maintenance of parish registers that applied to churches in England did not apply in Scotland.
An important point is that several of the baptisms on that page have the child's name missing.
I think it is unlikely the name was omitted simply because the child died in infancy. Usually an infant received his or her name at baptism (christening), and you know this child was baptised, so it is unlikely he or she was unnamed. You can also rule-out the child being stillborn because a stillborn child would not be baptised.
Exactly how the minister or clerk compiled this baptism register is impossible to know, but he may not have recorded the entries at the exact time of the event. He may have made a list of the upcoming baptisms that week and then entered them in the register all at once, intending to add (in this case failing to add) the child's name when the child was christened. He may have been lax in recording the events and a week or two later tried to remember what baptisms occurred, but couldn't remember the child's name. He may have written down the information on a scrap of paper at the time of the baptism, but then lost it or couldn't read his own handwriting when copying into the register.
I could go on producing more fanciful scenarios that result in a child's name being omitted, but I would just it down to poor record-keeping.
So where might you look for more information about this child?
If this were an event in England, my first port-of-call would be taking a look at the Bishop's Transcripts, which were contemporary copies of the parish registers. Alas, no such transcripts were made in Scotland, so you're out of luck there.
As I suspect you have done, you can scour the burial or death registers for the parish looking for a corresponding entry. One would expect an infant or child to appear in the register but of course it is prone to all the same sorts of errors and omissions of baptism registers – perhaps more so, since infants might be buried in the grave of an (unrelated) adult.
You might try looking in Kirk Session Minutes for the parish. I would not be extremely optimistic that you will find anything about this child in these records, since this is more typically a place to find information about poor relief, illegitimate births, etc. – but you never know what the minute-taker thought worthy of note.
Consider records pertaining to inheritance after the child's parents died, including wills and testaments or sasines (if you are lucky and they were land-owners). This is of course assuming the mystery child survived infancy.
It is unclear why FamilySearch have recorded this as a male child. The register simply says "child", not "son", so I would be careful making any assumptions about the sex of the child. Especially if the child was a boy, you may find him in apprenticeship records or other occupational records.
You might need to search randomly for Drumonds in the area who married or were having children in the 1750s-1770s, and see if any likely links turn up in terms of naming patterns (some Scots adhered closely to traditional naming patterns). You might have to go down many false trails before you pick up on a likely possibility for the identity of this child.