Hi,
Browsing the photos in the gallery, it seems that swiping up deletes a photo. It is possible to undo it until you swipe to the next photo. Is there a way to revcover the photo after having swiped?
I got bitten by that behaviour, and I find it very error prone.
Thanks in advance
Regain your privacy! Adopt /e/ the unGoogled mobile OS and online services
I use an alternate app from F-Droid: Simple Gallery Pro, which has an optional “Recycle Bin” function. It makes it easy to restore mistakenly deleted photos.
Sorry, can’t help with the default /e/ Gallery. 
Thanks for the tip, I hope someone can help with the default Gallery. I can’t believe it is so easily deleted with no recover option.
As far as I know, there’s no recovery in Android, unless the phone is rooted. Unfortunate, since your deleted files are still there somewhere until overwritten. There are some apps available (usually not privacy-friendly) that function as a master recycle bin, but I don’t think they’ll help with deletions made prior to installing the app.
It might be a good idea to prevent such easy delete by mistake in the default gallery.
I think what I did was display a photo. In that situation you can swipe to next and previous photo. I unzoomed and you get a similar view as the previous but with the picture somewhat smaller. You can swipe to the next and previous photo too. But in this view, you can delete by sending the photo upwards. I did this by mistake when trying to unzoom again to get to the gallery view (which is not the way to get back to the gallery anyway 
). The undo option disappeared because I swiped to the next photo, probably in the same movement as the unzoom that deleted the photo.
Do you sync your photos to cloud, by any chance?
Well, I have sync to cloud, but not all photos seem to be there, and the one I need is not there.
Not sure how comes not everything is synced.
But I won’t search further. Thanks for your attention @Taurus