How to fit a picture neatly in a frame
Layout by Zaweba fits pictures with fill or fit proportionally, content to frame, frame to content, centre, content-aware fit and auto-fit.

Choose a fitting option once a picture is in its frame in Layout by Zaweba. Fill proportionally covers the whole frame without distorting the picture, cropping whatever spills over. Fit proportionally shows the whole picture inside the frame, leaving space where the shapes differ. Fit content to frame stretches it to match exactly, fit frame to content resizes the frame around the picture, centre puts it in the middle, and content-aware fit looks for the important part of the picture to keep in view.
A frame and the picture inside it are two different things. The frame is the window; the picture is what you see through it. Fitting options are quick ways of deciding how the two relate, and they save a lot of dragging by eye.
Which fitting option to use
Fill proportionally is the everyday choice for photographs in a designed grid. Every frame is filled edge to edge, nothing is squashed, and a little of the picture is cropped. Fit proportionally suits pictures that must be seen whole, such as a product cut-out or a chart, where cropping would lose something.
Fit content to frame stretches the picture to the frame's exact shape, which distorts it unless the proportions already match. It is rarely right for photos and is mostly useful for flat graphics.
Fit frame to content is handy when the picture's own shape is what you want, such as a logo placed at its natural proportions. Centre is a quick way to recentre after a nudge.
Content-aware fit is the helpful one for busy pages. It looks at the picture and places the crop so the subject stays in view, which saves adjusting dozens of frames one by one in a catalogue or a photo-heavy magazine.
Auto-fit for layouts that change
Auto-fit keeps the fitting rule in force when the frame changes size. Turn it on and you can resize a frame while trying out a layout, and the picture refits itself each time. It is a real time saver when a design is still moving.
Crop amount gives you a set figure for the crop rather than a judgement by eye, which helps when several pictures need to be cropped alike.
Cropping and fine adjustment
After fitting, you can still move and scale the picture inside the frame to set the crop by hand. Frame within frame, using paste into, lets you put a picture inside a shape that sits inside another frame, which is useful for layered designs.
Clipping paths, made from detected edges or an alpha channel, hide the background of a picture without changing the frame. Display quality can be set to fast, typical or high, so a long document stays responsive while you work and you can still check detail when you need to.
Getting a good result
Decide the fitting rule early and use it consistently. A page where every picture fills its frame looks orderly. Mixing filled and fitted pictures on the same spread looks unplanned unless it is clearly deliberate.
Don't enlarge too far. Filling a big frame with a small picture scales it up, and the Links panel's effective ppi tells you whether it is still sharp enough to print. Live preflight can flag low-resolution pictures too, which catches the ones you scaled up during a hurried layout.
For repeating designs, object styles keep frames of the same kind consistent, and settling on a fitting rule per kind of frame is what makes a fifty-page catalogue as easy to keep in order as a single page.