But do you usually edit images on laptop's local storage or external LAN-Wired storage?
That depends on your workflow, your network reliability, and how do you plan to backup data.
Working on a local copy is of course faster, and you remove a good slice of equipement that could corrupt a file from the path (network card, network devices, ecc.), especially when editing implies making many changes to a file. Performing backups or syncs of files is usually safer, because it implies accessing the whole file, and good software calculates a "fingerprint" of the file (CRC, hash, whatever) before copying it, and then compares it after it has been copied, and can thereby spot any error.
And if your only copy of the files are on the remote storage, of course you also need a backup on a separate storage. But if you need to access the same files from different devices, without attaching the storage directly each time, you may need to share them via a remote storage.
That said, it's not unusual, especially in some business environment, to work on remote files - but the whole "path" to the files needs to be "safe" enough, and that means devices, cables, power supply, etc. etc. to minimize troubles. IMHO, in such a situation working via a cabled network is better than via WiFi.