iPhones default gallery app, Photos, is more smart than you think.
It not only provides photo/video management features but also something called Memories.
What is Memory Mix in the Photos App?

How to Add Photos and Videos to Memories?
To add photos and videos to Memories, launch thePhotosapp on your iPhone.
When the Photos app opens, switch to theFor Youtab at the bottom.

Next, tap on theMemoriestile you want to edit.
On the next screen, tap thethree dotsin the top right corner.
On the menu that appears, selectManage Photos.

Select thePhotos or videosyou want to include on the Memory Montage.
To apply the changes, tap onDoneat the top right corner.
If you wish to rearrange the photo/video position, tap theGridicon at the bottom right corner.

To reposition the photo/video, you should probably tap and hold the items.
Once selected,drag it aroundto reposition it.
How to Remove Photos and Videos from Memories?

To remove photos and videos from Memory Montage, stick to this.
Launch thePhotosapp on your iPhone and launch the Memory you want to edit.
Tap on thethree dotsat the top right corner and selectManage Photos.

Now, you will be able to see all images/videos that are included in the Memory.
You need tounselect the Photos/Videosthat you dont want to appear in the Memory.
Once done, tapDoneat the top right.

Alternatively, long press on the Photo/Video and selectHide from Memoryoption.
How to Hide Apps in Realme Phones
Google Chrome Not Saving Password?
8 Ways to Fix it
How To Fix Mobile Hotspot Connected but No Internet on Android

