This (minor/silent) error has a simple cause – the showDetails method in SearchResults.vue (which gets called every time the user clicks an image or video thumbnail in the search results) includes code to ensure that the sidebar Quickview panel is scrolled into view properly (it's possible the quickview element will be taller than the current viewport, and we want the user to always see the top of it when it first expands).

The problem is, the sidebar (<aside> element) only exists in desktop view, not in mobile. So we need to check for the appropriate $ref before trying to programmatically scroll it into view.

Will upload a patch for this shortly.

Change 704577 had a related patch set uploaded (by Eric Gardner; author: Eric Gardner):

[mediawiki/extensions/MediaSearch@master] Quickview: don't use "aside" $ref on mobile skin

https://gerrit.wikimedia.org/r/704577

Change 704577 merged by jenkins-bot:

[mediawiki/extensions/MediaSearch@master] SearchResults: don't call on "aside" ref when it doesn't exist

https://gerrit.wikimedia.org/r/704577

There are still errors: undefined is not an object (evaluating 'this.$refs.aside.scrollIntoView') on Special:MediaSearch dashboard, the latest timestamp =Jul 29, 2021 @ 00:33:34.057

$schema /mediawiki/client/error/1.0.0
@timestamp Jul 29, 2021 @ 00:33:34.057
@version 1
_id TqSu73oBmhjHfZRTUCkA
_index logstash-2021.07.29
_score - 
_type
_doc
error_class TypeError
file_url https://commons.m.wikimedia.org/w/load.php?lang=en&modules=jquery%2Cmediasearch&skin=minerva&version=sj2da
http.request_headers.user-agent
Mozilla/5.0 (iPhone; CPU iPhone OS 13_6 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/13.1.2 Mobile/15E148 Safari/604.1
level ERROR
message undefined is not an object (evaluating 'this.$refs.aside.scrollIntoView')
meta.domain commons.m.wikimedia.org
meta.dt 2021-07-29T00:33:32.995Z
meta.id 0d63b43b-df1e-4887-ac2e-c24b59a70fc2
meta.request_id df3ebee2-e4af-48e7-adcc-d797ab9293c2
meta.stream
mediawiki.client.error
normalized_message undefined is not an object (evaluating 'this.$refs.aside.scrollIntoView')
stack_trace
at https://commons.m.wikimedia.org/w/load.php?lang=en&modules=jquery%2Cmediasearch&skin=minerva&version=sj2da:212:472
at https://commons.m.wikimedia.org/w/index.php?search=speed&title=Special:MediaSearch&type=video&haslicense=unrestricted:210:317
at qe https://commons.m.wikimedia.org/w/index.php?search=speed&title=Special:MediaSearch&type=video&haslicense=unrestricted:209:714
tags input-kafka-clienterror-codfw, kafka, es, es, throttle-exempt, normalized_message_untrimmed
type clienterror
url https://commons.m.wikimedia.org/wiki/Special:MediaSearch?search=fire&title=Special:MediaSearch&type=video&haslicense=unrestricted

There are also similar (identical?) error reports:
normalized_message Cannot read property 'scrollIntoView' of undefined

ping @egardner I checked again - the last timestamp:

@timestamp Jul 29, 2021 @ 19:53:16.412

Re-checked:
logstash error: Cannot read property 'scrollIntoView' of undefined - the last timestamp -Aug 3, 2021 @ 05:38:26.102. All errors (total count - 9) for the last 24 hours) are coming from mobile.

logstash error:undefined is not an object (evaluating 'this.$refs.aside.scrollIntoView') - the last timestamp - Aug 2, 2021 @ 23:26 All errors (total count - 6) for the last 24 hours are coming from mobile.