Match the product descriptions
Ask for the door model, construction, finish and glazing in each proposal. If one quote includes a different assembly, treat it as a different option rather than an unexplained price discrepancy. A broad description such as insulated steel is not the full specification.
Separate reused and replaced equipment
Record whether the opener, controls and other components are retained or supplied new. Ask why any reuse is considered appropriate. This makes it easier to evaluate the proposal and prevents a later disagreement about whether a component was included in the replacement project.
Identify exclusions and dependencies
Clarify removal, site preparation and any separate work needed before installation. Ask who confirms the schedule once the product and prerequisites are ready. Keep changes to the accepted scope in writing so the final invoice can be understood against the original decision.
Your questions
Can two similar photographs mean the quotes are equivalent?
No. Images can hide differences in construction, glazing and supplied equipment. Compare the written specifications and included work.
Is a preferred appointment date a confirmed installation?
Only after the provider confirms it. Product availability and any unresolved preparation can affect when the work can be scheduled.